فهرست نشریات علمی دسترسی آزاد ایران

In this study, a highly sensitive recyclable colorimetric chemosensor for the detection and determination of copper (II) and L-cysteine (Cys) was presented, which uses an optical color change based on an indicator displacement assay (IDA). This chemosensor was designed and fabricated using the xanthine dye, bromopyrogallol red (BPR), an easy-to-prepare dye. The label exchange between BPR and Cys occurred upon adding of cysteine to the BPR-copper (II) complex, resulting in a clear and immediate color change from blue to purple in DMSO/MES buffer at 10.0 mmol L-1, pH 5.0 (1:4 v/v). The proposed method exhibits a detection limit of 80.0 nmol L-1 and a reasonable linear range from 0.79 to 21.00 μmol L-1 for cysteine. Furthermore, based on the absorbance changes and color changes produced, this chemosensor is proposed as an “IMPLICATION” logic gate (IMP) to evaluate the inputs of Cu2+ and cysteine. Based on the fast response and repeatability, a molecular-scale sequential memory unit is designed to exhibit “keypad lock” behavior. The extended receptor offers satisfactory repeatability and good accuracy and is used for the selective determination of cysteine in human blood plasma and urine. Furthermore, the method's accuracy was compared with the results of the proposed method by high-performance liquid chromatography (HPLC).