Acetazolamide smartphone-based detection via its competition with sulfamethoxazole on molecularly imprinted polymer: A proof-of-concept.

In this work, a competitive assay based on molecularly imprinted polymer (MIP) is developed for the rapid screening of acetazolamide (ACZ) using a colorimetric method coupled with smartphone-based detection. Because of it is an analog of ACZ and its ability to be transformed into a colored product, sulfamethoxazole (SMX) was used as a competitor to indirectly determine ACZ from the inhibition degree of SMX onto the MIP. It was found firstly that ACZ-SMX competition was not possible without using support. We proceed after that to competition on MIP that is a propitious platform for adsorbing selectively both molecules since it possesses specific active sites. Indeed, two different MIPs were synthesized, namely SMX-imprinted polymer (MIP) and ACZ-imprinted polymer (MIP), and the results showed that MIP is better for ACZ-SMX competition. Both MIPs were characterized with Fourier transform infrared spectroscopy. The smartphone was employed for taking images and analyzing color intensities by (RGB) color application. Our proposed detection method of ACZ reached 0.03 and 0.1 µM as limits of detection and quantification, respectively. The developed assay was successfully applied for the determination of ACZ in pharmaceutical drug and mineral water samples showing satisfactory recoveries. The proposed proof-of-concept based on the rapid screening of ACZ by competition method and smartphone was demonstrated successfully and thus can open new avenues for other applications.