Molecularly Imprinted Polymers-Based Optical Sensors for Biomedical Diagnostics

Molecularly imprinted polymers (MIPs) are custom-designed artificial receptor materials that have the ability to identify and selectively attach with specific target molecules such as proteins, small organic molecules, or ions. The molecular imprinting process used to create MIPs entails synthesizing the polymer from its monomers with cross-linking agents while the target molecule is present in the matrix. This results in the formation of precise binding sites in the polymer network that mirror the shape and chemical properties of the template molecule. MIPs have gained significant attention in various fields, including chemical sensing, biosensing, environmental monitoring, and healthcare monitoring. MIPs can be integrated into optical sensors as a thin film or coating on a solid substrate and used to detect specific target molecules. MIP-based optical sensors may use optical absorbance/transmission, fluorescence, or surface plasmon resonance (SPR) phenomenon as the signal transduction mechanism. Consequently, variations in the absorbance, fluorescence, or refractive index of the sensor material, resulting from the binding of the target molecule, can be identified and employed for the quantification of the target analyte’s concentration. MIP-based optical sensors offer many advantages, such as good specificity, sensitivity, and reusability. As a result, they have been applied for the recognition of a diverse analytes, encompassing drugs, toxins, and biomolecules. Optical sensors utilizing molecularly imprinted polymers (MIPs) have shown promise in disease detection and monitoring due to their ability to provide highly specific and sensitive detection of biomolecules associated with various diseases making them useful for applications in healthcare and diagnostics. In the present chapter, the fundamental principles MIP-based optical sensors have been discussed. The signal transduction mechanisms including absorbance, fluorescence, and SPR-based techniques have been presented. In addition, the fabrication process involving integration of MIP into optical sensor devices and functionalization of MIP has been discussed. In this chapter, we delve into the fundamental principles, working mechanisms, and fabrication of MIP-based optical sensors. We converse about practical applications of these sensors in disease detection and monitoring, drawing examples from recent research findings.