Application of modifier-free gold nanoparticle colorimetric sensing for rapid screening and detection of vitamin B1
In this report, we present a transparency sheet-based colorimetric sensor as an alternative platform for the simple, sensitive and selective determination of vitamin B1 in urine samples by using unmodified gold nanoparticles (AuNPs). Samples presenting different concentrations of vitamin B1 were evaluated. The specific analysis is based on the aggregation of AuNPs by vitamin B1 due to the ability to form strong electrostatic interactions between positively charged vitamin B1 and negatively charged AuNPs. In the presence of vitamin B1, a distinctive color change in the AuNPs from red to blue was visualized by the naked eye within 10 minutes without the requirement for surface modification. For quantitative measurement using image processing, a good linear relationship (R2 = 0.9913) between the vitamin B1 concentration and average red intensity was obtained in the range of 40–200 ppb. The limit of detection (LOD) and the limit of quantitation (LOQ) for vitamin B1 were found to be 3.002 ppb (S/B = 3) and 10.006 ppb (S/B = 10), respectively. The characteristics of the developed sensors were investigated for precision, accuracy, and sensitivity, and they were validated by classic methods. Statistical analysis proved that the developed sensors were precise, sensitive and accurate and that they can be used effectively for the analysis of vitamin B1 in urine samples.