Colorimetric Detection of Ascorbic Acid Based on the Trigger of Gold Nanoparticles Aggregation by Cr(III) Reduced from Cr(VI)

• Published in: Analytical Sciences Vol. 33; no. 8; pp. 963 - 967
• Main Authors: SUI, Ning, LIU, Fengya, LI, Tailing, WANG, Lina, WANG, Tao, LIU, Manhong, YU, William W.
• Format: Journal Article
• Language: English
• Published: Singapore The Japan Society for Analytical Chemistry 2017; Springer Nature Singapore; Japan Science and Technology Agency
• Subjects: Agglomeration; aggregation; Analytical Chemistry; Ascorbic acid; Chemistry; Chromium; Color; Colorimetry; Cr(III); Cr(VI); Gold; Gold nanoparticles; Nanoparticles; Selectivity; Tripolyphosphate; Vitamin C; ascorbic acid; aggregation; Cr(VI); Gold nanoparticles; Cr(III)
• ISSN: 0910-6340; 1348-2246
• DOI: 10.2116/analsci.33.963

Au nanoparticles (AuNPs) dispersed in water were stabilized by tripolyphosphate (P3O105−). When Cr2O72− (Cr(VI)) was present, the AuNPs did not change; when Cr3+ (Cr(III)) was present, the AuNPs would aggregate because of cooperative metal-ligand reaction. Aggregated AuNPs showed different color from the non-aggregated ones. Thus, a simple colorimetric assay was made using AuNPs-Cr(VI) to detect ascorbic acid (AA). Upon introducing AA to the AuNPs-Cr(VI) system, Cr(VI) was reduced to Cr(III), and the aggregation of AuNPs occurred. This colorimetric assay performed high selectivity and a linear concentration response in the range of 0.2 to 10 μM; its limit of detection was 0.15 μM.