Histidine-functionalized silver nanoclusters used as a blue-emissive fluorescence probe for vitamin B12 detection

Vitamin B12 is a drug that can participate in the production of bone marrow red blood cells, prevention of pernicious anemia and damage to brain nerves. It is needful to prepare new vitamin B12 determination strategies with excellent sensitivity, selectivity and uniqueness. Herein, a novel and facile chemical reduction method was successfully carried out (histidine and ascorbic acid were applied as protectant and reductant) for preparing histidine-functionalized silver nanoclusters (Ag NCs@his) with blue fluorescence. Some technologies were adopted to clarify the structure, optical characteristics of this stable Ag NCs@his and fluorescence quenching mechanism. Based on inner filter effect, a sensitive and selective platform for vitamin B12 detection was established. Under optimum pH value, reaction time and temperature, the as-developed platform could be utilized to the trace measurement of vitamin B12 with linear range of 0.5–200 μM and detection limit of 0.038 μM. Moreover, this platform was successfully used to measure vitamin B12 in real samples and temperature.