In situ production of silver nanoparticles for high sensitive detection of ascorbic acid via inner filter effect

- A sensitive and simple method has been developed for detection of ascorbic acid.
- Silver nanoparticles as a strong quencher were prepared via the one-step reduction.
- Its absorption band covered both emission and excitation bands of CdTe QDs.
- So, the fluorescence of CdTe QDs quenching due to Inner filter effect.

In the present research, a sensitive biosensing method was proposed for the detection of trace amounts of ascorbic acid (AA). Herein, colloidal silver nanoparticles (SNPs) were successfully in-situ produced by chemical reduction of silver ion in the presence of AA, as a reducing agent. The one-pot in-situ produced silver nanoparticles were characterized by UV-vis, dynamic light scattering (DLS), zeta potential and transmission electron microscopic (TEM). SNPs act as a strong fluorescence quencher for the CdTe quantum dots via an inner filter effect (IFE). Since the absorption band of SNPs entirely covered both emission and excitation bands of QDs. Therefore, the decreasing in the fluorescence signal depends on the AA concentration in the linear range of 0.2-88.0 ng mL− 1 and with a detection limit of 0.02 ng mL− 1. Relative standard deviations of 2.3% and 2.8% (n = 5) were achieved for the determination of 1.8 and 8.8 ng mL− 1 AA, respectively. This novel QDs nanosensor based on IFE could provide noticeable advantages of simplicity, convenience, cost-effectiveness, and sensitivity. This method was successfully applied for the detection of ascorbic acid in human real samples serums.