Design of a Lab-on-Chip Cartridge for the Optical Detection of Small Molecules Based on Dye-Displacement MIPs

Molecular imprinted polymers (MIPs) are well known for their specific recognition of a wide variety of different analytes. However, the complex immobilization process of MIPs onto sensor electrodes poses a significant challenge. This research introduces a novel approach to enhance the application potential of MIPs by exploiting dye-displacement MIPs. These synthetic receptors can selectively release dye upon exposure to an aqueous target. A disposable and low-cost lab-on-chip cartridge is presented, enabling the MIPs to interact with the target solution for dye displacement. Furthermore, these cartridges are coupled to a portable optical sensor setup that can be used for screening samples in a user-friendly and fast manner. Characterization experiments demonstrate the capability of the spectrometer setup to identify different color dyes and intensities. Finally, a proof-of-application shows the use of our sensing setup for the indirect detection of 2-methoxphenidine (2-MXP) using dye-loaded MIPs, employing a dose–response characterization (4PL). Furthermore, as the dye displacement and sensing principle are universal, this setup holds promise for various other sensing applications, including food quality assessment, environmental testing, and pharmaceutical analysis.