GA-AuNP@Tollens' complex as a highly sensitive plasmonic nanosensor for detection of formaldehyde and benzaldehyde in preserved food products.

Food preservatives nowadays are widely used chemicals throughout the food industries due to their commercial importance in increasing the shelf life of foods. But daily consumption of these preserved food products may be fatal to human health. Among different aldehydic compounds, formaldehyde and benzaldehyde are mainly used for preservation. Therefore, we reported a study on simple, selective and sensitive non-enzymatic detection of formaldehyde and benzaldehyde using GA-AuNP@Tollens'. Plasmonic resonance of GA-AuNP@Tollens' was taken as the basis for sensing formaldehyde and benzaldehyde in the linear range of 10-150 nM and 0.15-0.75 µM respectively. Both optimization and detection were acquired at UV absorbance of 409 nm. Detection limit of formaldehyde and benzaldehyde obtained through the proposed method was 20.08 nM and 0.12 µM respectively. Smartphone based detection method showed good linearity with R-Square value of 0.95 for both analytes. Lastly, GA-AuNP@Tollens' was implemented for the quantification of analytes in real samples.