Specific quantification of atropine using molecularly imprinted polymer on graphene quantum dots

Herein, development of a reliable and specific fluorometric assay was disclosed for the sensitive detection of atropine. The method was designed using the surface molecularly imprinted polymer on high fluorescent graphene quantum dots (GQDs). Molecularly imprinted polymer capped GQDs (MIP-GQDs) were prepared through the common co-polymerization reaction of 3-(3-aminopropyl) triethoxysilane (APTES) and tetraethyl orthosilicate (TEOS), act as the main functional and cross-linking monomers, respectively. The used template for this reaction was atropine. The created blue luminescent MIP-GQDs composite, which had a great affinity to adsorb atropine from the sample solution, could lead to a notable fluorescence quenching. In fact, GQDs act as the recognizing antenna for adsorbed atropine into the specific MIP sites. The linear association between the observed quenching effect and atropine concentration was exploited to design a selective assay to the detection of atropine. After optimization process, a linear calibration graph was achieved in the atropine concentration range of 0.5–300 ng mL⁻¹ with a detection limit of 0.22 ng mL⁻¹. Exploitation of high specific MIP technique along with high fluorescent GQDs provided a highly selective and sensitive assay for atropine as a model analyte. It was adequately utilized for the analysis of atropine in biological samples.