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 nano-sensors 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.