Vitamin B12 Detection in Aqueous Media Using MPA-CdTe Quantum Dots

In this letter, we present a sensitive approach for the qualitative and quantitative detection of vitamin B12 (VB-12). The method utilizes dual-capped CdTe quantum dots (QDs) as a fluorescent probe. These QDs were synthesized through a one-pot synthesis method in an aqueous medium. Various factors affecting the accuracy of VB-12 determination were systematically investigated to establish optimal conditions. The resulting calibration curve, spanning the concentration range of 10–300 ng/mL of VB-12, exhibited a linear relationship, with a limit of detection and a limit of quantification of 0.326 ng/mL (0.3 nM), and 1.22 ng/mL, respectively. Additionally, the interaction mechanism responsible for the fluorescence quenching of CdTe QDs by VB-12 was discussed. The proposed method holds promise for sensitive and accurate VB-12 detection and may have applications in analytical chemistry and medical diagnostics.