Aggregation-Induced Emission Probe for Specific Quantification of Creatinine

Creatinine is the metabolic waste molecule and naturally produced by the body from muscle metabolism. Abnormal creatinine levels in body fluids (blood and urine) implies the decrease in kidney functional activity[1]. Therefore, CRN serves as a preferred marker for renal dysfunction. The glutathione capped Cu-nanoclusters presented here showed a unique aggregation-induced emission (AIE) feature[2]. This novel AIE phenomenon was successfully exploited for selective and sensitive quantification of typical uremic toxin creatinine. When the CuNCs encountered Al3+ ions, they rapidly formed aggregates which induce significant emission enhancement of CuNCs. The AIE nature of CuNCs was proved via the TEM and enhanced emission in poor solvents. Moreover, the coordination between CRN and Al3+ ions could lead to the quenching of fluorescence due to the weakening the AIE. Quenched PL intensity showed a linear dependence on the concentrations of CRN in the in the range of 2.5– 34 µgL-1 with a detection limit of 0.63 μgL−1 and excellent selectivity for CRN. The sensing mechanism of the AIE based fluorescence probe for CRN detection was discussed. Also, the developed probe was applied to determine in CRN human serum and urine samples with satisfactory results.