Preface

Over the years, the field of biosensors has experienced tremendous change due to the development of highly sensitive, rapid, and specific sensing devices made possible by cutting-edge technology and scientific advancements. This book, *New Advances in Biosensing*, is a comprehensive exploration of the fascinating realm of biosensing technologies and their diverse applications.

Biosensors have recently become essential devices in many sectors, such as biotechnology, environmental monitoring, and medical care. The integration of solid-state sensors, wearable sensors, nanostructure-based electrochemical strategies, and microfluidic devices has completely changed the way we can accurately and efficiently detect and evaluate biological and chemical analytes. This book contains contributions from leading experts and researchers in the field. Through its chapters, readers will embark on a journey into the intricacies of microfluidic biosensors, delve into the principles of electrochemical biosensors, explore the remarkable properties of nanostructures in sensor design, uncover the potential of wearable sensors, and understand the robustness of advanced sensors. Each section offers an in-depth review of the relevant technology, encompassing both theoretical underpinnings and real-world applications. We believe that everyone who wants to understand the fundamentals of contemporary biosensing technologies - scientists, engineers, professionals, and students - will find this book to be an important resource. We hope that the information provided in these pages will stimulate more creativity and research, leading to the creation of biosensors that can help solve today's most important problems.

We extend our thanks to the authors for their hard work, and we hope that readers will find this anthology useful, motivational, and beneficial in their quest for biosensor technology breakthroughs. We are especially grateful to Emir Ersel Karakuş and the editorial team at IntechOpen for their assistance in preparing this book.

> **Selcan Karakuş** Associate Professor, Faculty of Engineering, Department of Chemistry, Istanbul University-Cerrahpaşa, İstanbul, Turkey

Section 1


2.3.2. Selection of Indexes

The evolution of regional ecological environmental governance is determined by several factors. Natural conditions determine the basis of eco-environmental quality, but socio-economic factors are also important to change the regional eco-environmental quality [16,53]. To explore the driving forces and evolutionary mechanism of the ecoenvironmental quality in Qinghai Province, we selected 10 indicators on the basis of the natural conditions and socio-economic influences of the region (Table 3).

**Table 3.** The serial number and name of each factor.

GDP: gross domestic product.

#### **3. Results**

*3.1. Overall Characteristics of Changes in Territorial Spatial Pattern*

3.1.1. Horizontal Regional Differentiation of Territorial Spatial Pattern

Qinghai Province has obvious regional differentiation in territorial space level, portraying a strong agglomeration of the production and living spaces and the dominance of ecological spaces. In 2020, the proportion of production, living, and ecological spaces in the total area of Qinghai Province was 1.29, 0.13, and 98.57%, respectively. The production and living spaces are mainly concentrated in the eastern part of Qinghai (Xining City, Haidong City, south-eastern part of the Haibei Tibetan autonomous prefecture, Hainan Tibetan autonomous prefecture, and south-eastern part of the Haixi Mongolian Tibetan autonomous prefecture) having the largest proportion of ecological spaces that are mainly distributed in central and western Qinghai.

From the perspective of the spatial distribution of second-class places, the urban living spaces (ULS) and rural living spaces (RLS) in Qinghai Province are small and concentrated, and their spatial distribution is similar to those of agricultural production space (APS) and industrial production space (IPS). Grassland ecology space (GES) and other ecology space (OES) were the most widely distributed spaces. Notably, the GES were mainly distributed in the Haidong region and Qinghai-Tibet Plateau. The OES were mainly distributed in the Qaidam basin. The forestland ecological space (FES) is mainly distributed in the eastern margin of the Qinghai and Kunlun Mountains. The water ecological space (WES) is distributed in the whole region, but more concentrated in the western Qinghai-Tibet Plateau (upstream of the Three-River Headwaters region).

#### 3.1.2. Difference in Vertical Gradient of Territorial Spatial Pattern

The vertical gradient differentiation of territorial space in Qinghai Province was obvious (Figure 2). The widest and narrowest areas of the territorial space were located in areas having altitudes of 4500–5000 m and >5000 m, respectively. The area of the production and living spaces was inversely proportional to the altitude. There was no distribution of the production and living spaces above the altitude of 5000 m. The maximum area of the production and living spaces was at altitudes above 3000 m (5670.01 km2 and 689.23 km2, respectively). The ecological spaces fluctuated with the increase in the altitude; the maximum area of ecological spaces (205,502.94 km2) occurred at the altitude of 4500–5000 m above sea level.

**Figure 2.** Distribution of PLE space at different altitudes in Qinghai Province, China.

In terms of the spatial distribution of second-level land classes, the land areas of the APS, IPS, ULS, and RLS portrayed a decreasing trend with increasing altitude. Notably, the maximum numbers of APS, IPS, ULS, and RLS all appeared in the areas having altitude less than 3000 m. The areas of GES and OES portrayed a trend of initial decrease, followed by an increase. This was followed by a decrease with increasing elevation; notably, the maximum numbers of GES and OES appeared at altitudes of 4500–5000 m and <3000 m, respectively. The FES portrayed an initial increasing trend with increasing elevation, followed by a decreasing trend; the maximum number appeared at an elevation of 3500–4000 m above the sea level. The WES area portrayed a trend of fluctuation; the maximum number of WES occurred at an altitude of 4500–5000 m.

#### *3.2. Characteristics of Changes in Spatio-Temporal Patterns of Territorial Space*

From 1980 to 2020, the territorial space of Qinghai Province in the horizontal region portrayed the pattern characteristics of increasing production and living spaces and shrinking ecological spaces (Table 4). The area of production spaces increased from 8051.18 km2 in 1980 to 9262.22 km2 in 2020. The area of living spaces increased from 650.16 km2 in 1980 to 948.06 km2 in 2020. However, the area of ecological land decreased from 687,965.40 km2 in 1980 to 686,457.57 km2 in 2020.

**Table 4.** Structural changes of production-living-ecological space types in Qinghai Province from 1980–2020

 (km2/%).

From the perspective of the change degree of the secondary spatial structure (Figure 3), the proportion of the secondary spatial area in Qinghai Province in 2020 (from large to small) was: GES > OES > WES > FES > APS > RLS > IPS > ULS. In addition to the decrease in the FES and OES ratio (the areas decreased by 178.27 and 24863.98 km2, respectively), the APS, IPS, ULS, RLS, GES, and WES increased significantly (754.83, 456.21, 156.02, 141.88, 18269.69, and 5264.73 km2, respectively). The ULS and RLS areas portrayed an increasing trend; the GES and WES portrayed an initially increasing trend followed by a decreasing trend. The APS area portrayed a trend of fluctuation, IPS and OES portrayed an initial increasing followed by a decreasing trend, and FES portrayed a trend of a small drop.

Based on the change rate of the secondary spatial structure in Qinghai Province, we could deduce that, during 1980–2020, the growth rates of the areas of the IPS, ULS, and RLS were 5.66, 3.67, and 0.65%, respectively, while those of the FES and OES portrayed a decreasing trend (−0.02 and −0.24%, respectively).

**Figure 3.** Territorial spatial pattern from the perspective of Production-Living-Ecological space for the years (**a**) 1980; (**b**) 1990; (**c**) 2000; (**d**) 2010; (**e**) 2015; (**f**) 2020.


**6.3 Swing variables**

*Wavelet Transform and Complexity*

**6.1 Methodology and data**

**6.2 Noise reduction using wavelet**

**6. Arm swing analysis with wavelet**

differentiate PD and non-PD people. The parameters that can be considered as the most appropriate to discriminate patients are stance time, duration time, and test speed.

In gait analysis with wavelet was important to detect the gait phases; in this case, we were interested in obtaining a measure that allows quantifying the minimum and the maximum displacement of each wrist. For this reason, to generate spatiotemporal variables, we use multiple denoising methods that allow us to obtain a signal without big fluctuations; according to this, we use methods like Savitzky-Golay filter and wavelet decomposition [43]. In this chapter, we present the results

For this study, 25 patients (aged 45–87 years) and 25 controls (aged 46–88 years)

Since the original signals had fluctuations that could affect the analysis and processing, it was necessary to apply wavelet techniques to remove alterations and clean the signal. As showed in **Figure 5**, we apply three-level wavelet decomposition using Daubechies wavelet with eight vanishing moments. From this step, the

As a result of the wavelet decomposition, we obtain a clean signal to determine the relative displacement of the wrist, which allows to observe conditions such as rigidity and asymmetry in upper limbs. For the next step, we use the *a*3 signal.

*Approximation coefficient and detail coefficient for wrist signal, the sum of these coefficient level generates*

approximation coefficients at level 3 were used as clean signal.

were selected, and like in the gait analysis, PD patients were in an early stage of the disease. All participants with PD were under a dopaminergic agonist and were evaluated while in the "on" state. The absence of dementia and any other related to neurological conditions that affect gait was confirmed by an expert neurologist. All PD subjects were completely independent mobility and did not require a walking aid.

obtained of applied wavelet decomposition using db8 to wrist signals.

**12**

**Figure 5.**

*original signals (s = a 3 + d 1 + d 2 + d 3).*

The arm swing variables calculated using the signal provided by eMotion were arm swing magnitude, arm swing time, arm swing speed, and arm swing asymmetry; these variables are defined as follows:

$$\text{et al.} \,\,\text{[44]}, \,\text{is the outcome of the next equal}$$

$$\text{\textbullet} \qquad \text{ASA} = \frac{\begin{bmatrix} \text{45}^{\text{\textdegree}} - \text{arct} \left( \frac{ArmSwing\_{\text{mwing}}}{ArmSwing\_{\text{lm}}} \right) \end{bmatrix}}{90^{\text{\textdegree}}} \text{\textbullet } \textbf{100}\%$$


**2.1 Enrichment by extraction**

Extraction is the process of passing a chemical compound from a liquid phase into another liquid which is not mixed there with. The extraction of trace element into the organic phase is based on the incorporation of the trace element into a neutral structure. Neutral structures used in such a reaction; chelate, ion pair and covalent structures. In order to accurately measure trace elements, it is very important to separate and enrich the matrix before the analysis. Specific and sensitive methods are required for this.

**69**

selectivity is ensured.

*New Methods in the Synthesis of (Meth)Acrylamides and Application Chelating Resin…*

The trace elements at various levels in natural waters, wastewater, surface water and ground water are converted into chelates at a suitable pH and extracted into a small volume organic phase according to the sample. These elements taken into the organic phase are concentrated back to the aqueous phase directly or again and are determined by various determination techniques. Extraction is used not only in liquid samples but in solid samples to recover from matrix. The first step is to dissolve the sample. In chelate extraction the sample in the first aqueous phase is the appropriate reagent selection depending on the elements it contains. The reagent should form chelates with the desired trace elements and not form chelates with undesirable components. In this regard, chelates are also preferred in the extraction of trace elements, in particular in the alkali and alkaline earth compounds, or in samples containing them. Because chelating ligands do not generally form with

Ion pair complexes can also be extracted into organic solvents because they are neutral structures. It is difficult to derive quantitative equivalents or formulas in the extraction of ion pair complexes. Because ion pairs occur in the presence of extremely strong electrolytes. At the same time, a number of different ion strands can be found. Most inorganic complexes are used in extraction from ion pairs. Ion pairs usually occur between the anionic complexes formed by inorganic ligands and the H+

‐ ]. In the extraction process, selectivity is achieved by utilizing variants such as pH, side reactions in the aqueous phase, ligand, solvent type and temperature. Extraction efficiency is defined as the size of the amount of material passing from the

D = Corganic/ Caqueous (1)

aqueous phase to the organic phase. The dispersion rate is determined by D.

When the balance is established, Corganic, total concentration of analyte in organic phase; Caqueous, denotes the total concentration of the analyte in the aqueous phase. To increase efficiency in extraction processes; synergistic effect, co-extrac-

The use of precipitation methods in the separation of elements is based on the different solubility of the compounds in aqueous solutions. Collectors are used in quantitative separation of trace elements in solution by the method of co-precipitation. A large-surface precipitate with inorganic or organic character is formed, so that the adsorbed surface is adsorbed. The mechanism of co-precipitation depends on the physical and chemical properties of the trace element and the carrier and on the experimental conditions. According to this; three mechanisms in the form of

The carrier should be added to the sample solution so that sufficient amount of precipitate is formed. In order to prevent the adsorption of ions that may interfere, the amount of carrier should be as low as possible. Precipitation methods are mostly used for the separation of trace elements into single press as well as separating the main component from trace components. By controlling the precipitation pH,

ion.

*DOI: http://dx.doi.org/10.5772/intechopen.88685*

*2.1.1 Chelation extraction of trace elements*

alkali and alkaline earth alkalis.

tion and salt effect processes are utilized.

confinement, mixed crystal formation or adsorption.

*2.1.3 Enrichment with co-precipitation*

*2.1.2 Ion pair extraction*

[H+

, MLn+1

*New Methods in the Synthesis of (Meth)Acrylamides and Application Chelating Resin… DOI: http://dx.doi.org/10.5772/intechopen.88685*

### *2.1.1 Chelation extraction of trace elements*

The trace elements at various levels in natural waters, wastewater, surface water and ground water are converted into chelates at a suitable pH and extracted into a small volume organic phase according to the sample. These elements taken into the organic phase are concentrated back to the aqueous phase directly or again and are determined by various determination techniques. Extraction is used not only in liquid samples but in solid samples to recover from matrix. The first step is to dissolve the sample. In chelate extraction the sample in the first aqueous phase is the appropriate reagent selection depending on the elements it contains. The reagent should form chelates with the desired trace elements and not form chelates with undesirable components. In this regard, chelates are also preferred in the extraction of trace elements, in particular in the alkali and alkaline earth compounds, or in samples containing them. Because chelating ligands do not generally form with alkali and alkaline earth alkalis.

#### *2.1.2 Ion pair extraction*

*Trace Metals in the Environment - New Approaches and Recent Advances*

sufficient. The second term is the enrichment coefficient.

With enrichment techniques;

increased.

ing process.

enrichment methods;

• Enrichment factor

• Contamination

• Sample size

• Number of samples

• Time for enrichment

**2.1 Enrichment by extraction**

methods are required for this.

• The complexity of the technique

• Price and laboratory conditions.

The first one is the recovery efficiency. However, it is not always possible to achieve a large recovery value. At low concentrations, 90 or 95% recovery efficiencies are

The enrichment methods in the work analysis undertake important functions.

2.Instead of the original media components (matrix), the new and the appropri-

especially with the enrichment process used in combination with the dissolv-

The following criteria should be taken into account when selecting trace element

Extraction is the process of passing a chemical compound from a liquid phase into another liquid which is not mixed there with. The extraction of trace element into the organic phase is based on the incorporation of the trace element into a neutral structure. Neutral structures used in such a reaction; chelate, ion pair and covalent structures. In order to accurately measure trace elements, it is very important to separate and enrich the matrix before the analysis. Specific and sensitive

1.The ratio of the amount of trace element to the amount of media is

3.In the new environment, the analyte shows homogeneous distribution,

ate technique for the determination technique is created.

4.The standard preparation for calibration is made easier.

• Minimum concentration limits of trace elements

• Number of desired trace elements

• Recovery value of the method

• The method of determination following the enrichment method

**68**

Ion pair complexes can also be extracted into organic solvents because they are neutral structures. It is difficult to derive quantitative equivalents or formulas in the extraction of ion pair complexes. Because ion pairs occur in the presence of extremely strong electrolytes. At the same time, a number of different ion strands can be found. Most inorganic complexes are used in extraction from ion pairs. Ion pairs usually occur between the anionic complexes formed by inorganic ligands and the H+ ion. [H+ , MLn+1 ‐ ]. In the extraction process, selectivity is achieved by utilizing variants such as pH, side reactions in the aqueous phase, ligand, solvent type and temperature. Extraction efficiency is defined as the size of the amount of material passing from the aqueous phase to the organic phase. The dispersion rate is determined by D.

$$\mathbf{D} = \mathbf{C}\_{\text{organic}} / \mathbf{C}\_{\text{aquous}} \tag{1}$$

When the balance is established, Corganic, total concentration of analyte in organic phase; Caqueous, denotes the total concentration of the analyte in the aqueous phase. To increase efficiency in extraction processes; synergistic effect, co-extraction and salt effect processes are utilized.

#### *2.1.3 Enrichment with co-precipitation*

The use of precipitation methods in the separation of elements is based on the different solubility of the compounds in aqueous solutions. Collectors are used in quantitative separation of trace elements in solution by the method of co-precipitation. A large-surface precipitate with inorganic or organic character is formed, so that the adsorbed surface is adsorbed. The mechanism of co-precipitation depends on the physical and chemical properties of the trace element and the carrier and on the experimental conditions. According to this; three mechanisms in the form of confinement, mixed crystal formation or adsorption.

The carrier should be added to the sample solution so that sufficient amount of precipitate is formed. In order to prevent the adsorption of ions that may interfere, the amount of carrier should be as low as possible. Precipitation methods are mostly used for the separation of trace elements into single press as well as separating the main component from trace components. By controlling the precipitation pH, selectivity is ensured.

The use of the precipitation process to separate the main component from the work component is not common. Because when the main component collapses, it can also drag and drop work components together. This leads to substance loss.

### *2.1.4 Electrolytic enrichment*

The electrolysis method is used to separate trace amounts of heavy metals from various solutions. The composition of the electrolyte and sample, the type and shape of the electrode, the electrolysis cell and other experimental variables greatly affect the electrolytic deposition of an element. Potentially controlled electrolysis, as well as stripping methods, are widely used in the enrichment of trace elements.

#### *2.1.5 Ion exchange*

Ion exchange technique is a method of enrichment of trace elements. The ion exchange method can be practiced in three ways. The first is the rinsing technique that the solution and the ion exchanger interact in the same container. The second is the filtration technique in which the sample solution is held by ion-exchanging paper or membrane filter and the trace elements are kept. The third technique is the column technique which is the most commonly used technique in the application. In the rinsing technique, the solution containing the trace element ion is rinsed with resin. It is expected to establish a balance of time distribution. The resin is separated from the solution by filtration. The resin can be reacted with suitable solutions and trace elements can be determined by solution techniques or directly by solid analysis techniques. In the filtration technique, the sample solution is passed through an ion exchanger paper or membrane filter. Filter elements are determined by direct or degradation. In the column technique, large-volume solutions containing trace elements from the filled column with ion-exchange resin are passed to selectively hold them. These trace elements are attached with a smaller volume of eluent. This final volume can be further reduced by evaporation. Selectivity of the functional groups in the selection of ion exchangers, changing capacity, exchange rate, regeneration of the ion exchanger and use of the appropriate eluent are the considerations.

#### *2.1.6 Enrichment with evaporation*

It is a very convenient method for some elements that can be converted to volatile or easily volatile components. In fly enrichment, the volatility difference between the matrix and the trace element must be large. The separation by blowing can be done in two ways by blowing both the matrix and the trace element. However, in inorganic analysis, it is not common to enrich the trace elements by flying.

#### *2.1.7 Adsorption-enrichment*

The change in the concentration of a solid or a liquid on the boundary surface is called adsorption. This phenomenon arises from the accumulation of molecules or ions of the solute from the gas, liquid or any solution by adhering to the surface of a solid substance. The increase in concentration is called positive adsorption. The decrease in concentration is also called negative adsorption. Physical and chemical properties of adsorbent substances are the most important factors affecting the adsorption process. Solids, metals and plastics have more or less adsorption power. Some natural solids with high adsorption power; coals, clays, zeolites and various

**71**

**Figure 1.**

*Column technique processing steps.*

*New Methods in the Synthesis of (Meth)Acrylamides and Application Chelating Resin…*

metal sprouts, and artificial solids are activated charcoal, silica gel and special polymers. The amount of adsorbed substance in the solids having high adsorption

The solid phase extraction method is applied in three ways: rinsing technique, semi-permeable retaining disc filtration technique and column technique [30–35].

Solid phase extraction method is widely used in the column technique. Columns of different sizes can be used. This technique consists of four process steps: These

As column filler natural and artificial polymers, silica gel, alumina, florusil, octadecyl (C18); octyl (C8), ethyl (c2), cyano, phenyl, cyclohexyl, amino, diol,

quaternary amine, aromatic sulfonic acid, carboxylic acid can be used.

**3. Functional methacrylates from α-chloro-N-arylacetamides**

Synthesis of α-chloro-N-arylacetamide is as follows: potassium carbonate (K2CO3) (0.1 mol) and arylamine (1 mol) and are dissolved in 30 mL of anhydrous benzene. The reaction mixture is taken in a three-neck round bottom flask equipped with a magnetic stirrer, thermometer, and cooled to 0°C. After then chloroacetyl chloride (1.1 mol) are added dropwise to the solution and stirred at room temperature for 16 h. The organic layer is washed several times with diethyl ether and separation phase is filtered and dried over MgSO4. α-Chloro-N-arylacetamide is crystallized

from methanol. Yield: 80%. The synthesis reaction path is given in **Figure 2.**

The structure of the compoundα-chloro-N-arylacetamide is identified by the

): 3340 (NH); 3100–2800 (C─H); 1680 (>C═O);

**3.1 Synthesis of α-chloro-N-arylacetamide**

FT-IR techniques. FT-IR (cm−1

1580 (aromatic, C═C) [36, 37].

power varies depending on the surface size and porous structure.

*DOI: http://dx.doi.org/10.5772/intechopen.88685*

*2.1.8 Solid phase extraction*

*<IP_ADDRESS> Column technique*

process steps is given in **Figure 1**.

*New Methods in the Synthesis of (Meth)Acrylamides and Application Chelating Resin… DOI: http://dx.doi.org/10.5772/intechopen.88685*

metal sprouts, and artificial solids are activated charcoal, silica gel and special polymers. The amount of adsorbed substance in the solids having high adsorption power varies depending on the surface size and porous structure.

### *2.1.8 Solid phase extraction*

*Trace Metals in the Environment - New Approaches and Recent Advances*

*2.1.4 Electrolytic enrichment*

*2.1.6 Enrichment with evaporation*

*2.1.7 Adsorption-enrichment*

*2.1.5 Ion exchange*

The use of the precipitation process to separate the main component from the work component is not common. Because when the main component collapses, it can also drag and drop work components together. This leads to substance loss.

The electrolysis method is used to separate trace amounts of heavy metals from various solutions. The composition of the electrolyte and sample, the type and shape of the electrode, the electrolysis cell and other experimental variables greatly affect the electrolytic deposition of an element. Potentially controlled electrolysis, as well as stripping methods, are widely used in the enrichment of trace elements.

Ion exchange technique is a method of enrichment of trace elements. The ion exchange method can be practiced in three ways. The first is the rinsing technique that the solution and the ion exchanger interact in the same container. The second is the filtration technique in which the sample solution is held by ion-exchanging paper or membrane filter and the trace elements are kept. The third technique is the column technique which is the most commonly used technique in the application. In the rinsing technique, the solution containing the trace element ion is rinsed with resin. It is expected to establish a balance of time distribution. The resin is separated from the solution by filtration. The resin can be reacted with suitable solutions and trace elements can be determined by solution techniques or directly by solid analysis techniques. In the filtration technique, the sample solution is passed through an ion exchanger paper or membrane filter. Filter elements are determined by direct or degradation. In the column technique, large-volume solutions containing trace elements from the filled column with ion-exchange resin are passed to selectively hold them. These trace elements are attached with a smaller volume of eluent. This final volume can be further reduced by evaporation. Selectivity of the functional groups in the selection of ion exchangers, changing capacity, exchange rate, regeneration of the ion exchanger and use of the appropriate eluent are the considerations.

It is a very convenient method for some elements that can be converted to volatile or easily volatile components. In fly enrichment, the volatility difference between the matrix and the trace element must be large. The separation by blowing can be done in two ways by blowing both the matrix and the trace element. However, in inorganic analysis, it is not common to enrich the trace elements by

The change in the concentration of a solid or a liquid on the boundary surface is called adsorption. This phenomenon arises from the accumulation of molecules or ions of the solute from the gas, liquid or any solution by adhering to the surface of a solid substance. The increase in concentration is called positive adsorption. The decrease in concentration is also called negative adsorption. Physical and chemical properties of adsorbent substances are the most important factors affecting the adsorption process. Solids, metals and plastics have more or less adsorption power. Some natural solids with high adsorption power; coals, clays, zeolites and various

**70**

flying.

The solid phase extraction method is applied in three ways: rinsing technique, semi-permeable retaining disc filtration technique and column technique [30–35].

### *<IP_ADDRESS> Column technique*

Solid phase extraction method is widely used in the column technique. Columns of different sizes can be used. This technique consists of four process steps: These process steps is given in **Figure 1**.

As column filler natural and artificial polymers, silica gel, alumina, florusil, octadecyl (C18); octyl (C8), ethyl (c2), cyano, phenyl, cyclohexyl, amino, diol, quaternary amine, aromatic sulfonic acid, carboxylic acid can be used.

**Figure 1.**

*Column technique processing steps.*


**6.4** *Nigella sativa* **toxicity**

*N. sativa* has GRAS status in the United States [74]. A randomized, placebocontrolled study with 40 healthy elderly investigated the safety profile after daily intake of 1 g *N. sativa* seed powder for 9 weeks. Results found no statistical changes in any of the biochemical markers of cardiac, liver, and kidney function [105]. In 70 patients with chronic renal disease, 2.5 ml/day *N. sativa* oil for 12 weeks was safe and effective in improving clinical and biochemical parameters of kidney function without adverse events [106]. In a clinical trial with obese women, *N. sativa* oil (which is present in whole seeds and polar seed extracts), reduced body weight, VLDL cholesterol and triglycerides [107]. Traditional toxicity studies in rodents have been performed. In mice, hepatotoxicity was observed after 14-days of oral dosing at 6–21 g/kg body weight of *N. sativa* seeds water extract. No signs of hepatotoxicity were observed with methanolic and chloroform extracts. Body weight reductions were seen in methanolic extracts [108]. Similar findings were observed with the water extract in rats with increases in serum gamma-glutamyl transferase and alanine aminotransferase, but no changes in alkaline phosphatase and degeneration of hepatocytes [109]. In another rat study, 1 g/day for 6 weeks of whole *N. sativa* seeds were protective against hyperlipidemia to a similar extent as simvastatin without adverse effects to liver markers [110]. Human equivalent doses are 30–100 g *N. sativa* extracts per day for the mice study, and 10 g whole seeds per day for the rat study [80].