Highly efficient, multiplexed SERS sensing of para-aminobenzoic acid using reusable silver nanoarrays for environmental monitoring

Highly effective optical sensors can act as next-generation chemo-sensors, which can facilitate fast sensing with superior sensitivity, reproducibility and reusability characteristics. Here, we investigated the feasibility of thermally evaporated Ag nanoarrays as cost-effective and reusable substrates for multiplexed para-aminobenzoic acid (PABA) sensing for environmental remediation applications. SERS performances of Ag/Si sensors were investigated as a function of the thickness. The thickness of Ag nanoarrays was increased with evaporation time and a thickness of similar to 18 nm exhibited the highest SERS enhancement. Ag nanoarrays with narrower size distribution on Si exhibited three-fold SERS enhancement than Ag/glass. Simulation studies revealed 70 times higher enhancement in the electromagnetic field in Ag/Si than in Ag/Glass. Ag/Si sensor possesses high efficiency, reproducibility, excellent recyclability and a low detection limit near femtomolar levels for sensing PABA. Moreover, the developed sensor established multiplexed detection of PABA and R6G; demonstrated to be an excellent chemo-sensors for environmental applications.