INTEGRATION OF SIGNAL TRANSDUCTION INTO MOLECULARLY IMPRINTED POLYMERS FOR OPTICAL SENSING

Biomimetic sensors can be used in a wide range of applications to offer fast and accurate monitoring and quantification. Detection of analytes based on optical signalling is particularly interesting due to its high sensitivity and simple instrumentation. The molecular selectivity in traditional biosensors depends on biological macromolecules and living cells, the well-known bottle-neck components that limit the shelf life and increase the cost of biosensors. As robust synthetic materials having pre-designed molecular selectivity, molecularly imprinted polymers (MIPs) are ideal substitutes for antibodies and nucleic acids for building up biomimetic sensors.

During the past years we have developed several different approaches to introduce signal transduction mechanisms into molecularly imprinted polymers. The imprinted polymers have both built-in molecular binding selectivity and effective signal transduction, allowing the MIPs to act as robust optical sensors with a high molecular selectivity. Implementation of MIPs for selective molecular detection using surface enhanced Raman scattering (SERS) has been demonstrated. By combining slective molecular binding with Raman fingerprint signal, the MIP-SERS sensors are able to detect therapeutic drugs in complex samples. More recently we integrated fluorescence resonance energy transfer (FRET) process into MIPs to construct turn-on fluorescence sensors. The methods of polymer synthesis were based on: (1) non-destructive tagging of clickable MIP nanoparticles with a fluorescence acceptor, and (2) one-pot synthesis of fluorescent MIP nanoparticles using a customised fluorescent monomer. The fluorescent MIP nanoparticles synthesized using these new methods display high molecular selectivity and short response time, and can be used to achieve fast molecular detection without tedious sample preparation.

Figure 1. a) Implementation of MIP-SERS for selective detection of nicotine. b) Preparation of fluorescent MIP nanoparticles as turn-on fluorescence sensor.

References:

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[3] Q. Li, T. Kamra, L. Ye, Chem. Commun., 52, 12237-12240 (2016).