Nanomaterials as optical sensors for application in rapid detection of food contaminants, quality and authenticity

A rapid and accurate analysis of food quality and safety is essential for human safety and health. Optical sensors based on nanomaterials and nano-effects offer fast detection, simple operation, low cost, high specificity, and sensitivity, and therefore are widely used for food analysis. A variety of nanomaterials, including quantum dots, nano-porphyrin, nano-gold, nano-silver, upconversion nanoparticles, nanozymes, metal oxide nanomaterials and organic fluorescent molecules-based nanomaterials were successfully used as active components for optical sensors to detect harmful food contaminants as well as for quality and authenticity analyses. Most of these nanosensors rely on either optical instruments or visual colorimetric detection. This paper reviews the detection mechanisms of nanomaterial-based optical sensors as well as the enhancement mechanisms of their specificity and sensitivity. Properties of various optically active nanomaterials, as well as detailed applications of these nano-sensors, are deliberated as well. Despite a variety of optical nanosensors reported in the literature for various applications, including rapid detection of food contaminants, quality and authenticity, their commercialization is still in its infancy stage.