Fluorescent Nanotechnology: An Evolution in Optical Sensors

Background: The optical properties of nanomaterials have evolved enormously with the introduction of nanotechnology. The property of materials to absorb and/or emit specific wavelength has turned them into one of the most favourite candidates to be effectively utilized in different sensing applications e.g, organic light emission diodes (OLEDs) sensors, gas sensors, biosensors, and fluorescent sensors. These materials have been reported as a sensor in the field of tissue and cell imaging, cancer detection, and detection of environmental contaminants, etc. Fluorescent nanomaterials are helping in rapid and timely detection of various contaminants that greatly impact the quality of life and food that is exposed to these contaminants. Later, all the contaminants have been investigated to be the most perilous entities that momentously affect the life span of the animals and humans who use those foods which have been contaminated. Objective: In this review, we will discuss various methods and approaches to synthesize the fluorescent nanoparticles and quantum dots (QDs) and their applications in various fields. The application will include the detection of various environmental contaminants and bio-medical applications. We will discuss the possible mode of action of the nanoparticles when used as a sensor for the environmental contaminants as well as the surface modification of some fluorescent nanomaterials with anti-body and enzyme for specific detection in the animal kingdom. We will also describe some RAMAN based sensors as well as some optical sensing-based nanosensors. Conclusion: Nanotechnology has enabled us to play with the size, shape and morphology of materials in the nanoscale. The physical, chemical and optical properties of materials change dramatically when they are reduced to the nanoscale. The optical properties can become choosy in terms of emission or absorption of wavelength in the size range and can result in the production of the very sensitive optical sensor. The results show that the use of fluorescent nanomaterials for sensing purposes is helping a great deal in the sensing field.