Trace-level sensing of food toxins by flexible and cost-effective SERS sensors fabricated by pulsed-laser-deposition of gold nanoparticles on polycarbonate matrix

Abstract

In viewpoint of rapid onsite screening of food contaminants, flexible surface enhanced Raman spectroscopy (SERS) sensors are developed by pulsed laser deposition process (PLD) with plasmonic gold nanoparticles (AuNPs) on the polycarbonate (PC) polymer matrix in the current study. PC/AuNPs with varying laser ablation pulses (200 NLP to 5000 NLP) tailored the morphological, structural and optical properties with their size and shape confinements. SERS properties of the prepared flexible PC/AuNPs sensors were optimized with Raman probe dye Rhodamine 6 G (R6G). Exorbitant SERS efficiency with highest enhancement factor of 1.1 × 108 was noted with sensor prepared at 3000 NLP (PA 3000 NLP). Sensor surface uniformity exhibited greater signal reproducibility with low values of % RSD (7.8). The fabricated flexible SERS sensor (PA 3000 NLP) achieved sensing of the food toxins effectively even in their trace levels of 10 − 10 M for methyl orange (MO) and 10 ppm for Butylated hydroxy anisole (BHA). Mechanism of SERS sensing dominated the electromagnetic enhancement was correlated well with their properties. Since SERS sensing need not require any intricate analyte pre-treatment, the fabricated PA 3000 NLP flexible SERS sensor can find the food toxins in rapid time (< 2 min), projecting a portable platform to conserve food safety.