Development of a highly sensitive electrochemiluminescence sophoridine sensor using Ru(bpy)32+ integrated carbon quantum dots - polyvinyl alcohol composite film

A facile electrochemiluminescence (ECL) sensing platform for the sensitive analysis of sophoridine was constructed using Ru(bpy)32+/carbon quantum dots - polyvinyl alcohol composite film as modifier. The carbon quantum dots (CQDs) which have the ability to enhance the ECL intensity were synthesized through a simple hydrothermal method. As Ru(bpy)32+ was entrapped in the polyvinyl alcohol (PVA), it was beneficial to immobilize Ru(bpy)32+ efficiently on the GCE surface, and therefore a stable ECL signal could be obtained. In addition, the ECL response on the Ru(bpy)32+/CQDs/PVA composite system was greatly enhanced by sophoridine. Single-factor was applied to optimize the measurement conditions. The fabricated sophoridine sensor exhibited a well-proportional correlation between ECL intensity and the logarithm of sophoridine concentration in the range of 1.0 × 10−10-1.0 × 10−5 M, and the detection limit was 5.0 × 10−11 M (S/N = 3). Moreover, the detection of sophoridine in blood serum was successfully accomplished and a desirable result by using the ECL sensing system was achieved, which indicated that the fabricated ECL sensor has potential value in sophoridine monitoring in practical samples.