Specific fluorometric assay for direct determination of amikacin by molecularly imprinting polymer on high fluorescent g-C3N4 quantum dots

Abstract

Here, a specific and reliable fluorometric method for the rapid determination of amikacin was developed based on the molecularly imprinting polymer (MIP) capped g-C₃N₄ quantum dots (QDs). g-C₃N₄ QDs were obtained by facile and one-spot ethanol-thermal treatment of bulk g-C₃N₄ powder and showed a high yield fluorescence emission under UV irradiation. The MIP layer was also created on the surface on QDs, via usual self-assembly process of 3-aminopropyl triethoxysilane (APTES) functional monomers and tetraethyl ortho-silicate (TEOS) cross linker in the presence of amikacin as template molecules. The synthesized MIP-QDs composite showed an improved tendency toward the amikacin molecules. In this state, amikacin molecules located adjacent to the g-C₃N₄ QDs caused a remarkable quenching effect on the fluorescence emission intensity of QDs. This effect has a linear relationship with amikacin concentration and so, formed the basis of a selective assay to recognize amikacin. Under optimized experimental conditions, a linear calibration graph was obtained as the quenched emission and amikacin concentration, in the range of 3-400 ng mL^-1 (4.4-585.1 nM) with a detection limit of 1.2 ng mL^-1 (1.8 nM). The high selectivity of MIP sites as well as individual fluorescence properties of g-C₃N₄ QDs offers a high specific and sensitive monitoring method for drug detection. The method was acceptably applied for the measurement of amikacin in biological samples.

Keywords: Amikacin; Fluorescence; G-C(3)N(4) quantum dots; Molecularly imprinting polymer.