Micro/nanoplastics
have emerged as global contaminants of serious
concern to human and ecosystem health. However, identification and
visualization of microplastics and particularly nanoplastics have
remained elusive due to the lack of feasible and reliable analytical
approaches, particularly for trace nanoplastics. Here, an efficient
surface-enhanced Raman spectroscopy (SERS)-active substrate with triangular
cavity arrays is reported. The fabricated substrate exhibited high
SERS performance for standard polystyrene (PS) nanoplastic detection
with size down to 50 nm and a detection limit of 0.001% (1.5 ×
1011particles/mL). Poly(ethylene terephthalate) (PET)
nanoplastics collected from commercially bottled drinking water were
detected with an average mean size of ∼88.2 nm. Furthermore,
the concentration of the collected sample was estimated to be about
108particles/mL by nanoparticle tracking analysis (NTA),
and the annual nanoplastic consumption of human beings through bottled
drinking water was also estimated to be about 1014particles,
assuming water consumption of 2 L/day for adults. The facile and highly
sensitive SERS substrate provides more possibilities for detecting
trace nanoplastics in an aquatic environment with high sensitivity
and reliability.