A Smartphone-based Colorimetric Probe from (3-Aminopropyl)triethoxysiloxane-glutaraldehyde Complex for Hydrogen Peroxide Determination in Antiseptic Commercial Product

Abstract

This thesis aims to develop a smartphone-based colorimetric probe for hydrogen peroxide determination in an antiseptic solution. The colorimetric probe employed (3-aminopropyl)triethoxysiloxane-glutaraldehyde complex (APTES-GA) as a chemical reagent that could react to hydrogen peroxide and give off a bleached colorimetric product. The change of the brick-red color to a pale yellow can be observed through the naked eye and quantified using a smartphone-based digital image analysis method with the assistance of a custom-built photographic box. The parameters of APTES-GA preparation as a colorimetric probe were optimized. The method development for hydrogen peroxide detection was investigated including the effects of the color detection mode, the volume ratio of APTES-GA and sample solution, reaction time, and water content on colorimetric analysis. Under the optimum conditions, a linear calibration curve for the hydrogen peroxide was established in the range of 0.17 %w/v to 1.36 %w/v using green intensity (R2 = 0.9909) as an analytical signal. The limit of detections (LOD) and limit of quantifications (LOQ) were calculated from the standard error of y-intercept and slope of the calibration curve and obtained as 0.10 %w/v and 0.32 %w/v, respectively. The intra-day and inter-day precisions were 0.074 - 0.363 %RSD and 0.268 - 0.910 %RSD, respectively. The intra-day and inter-day accuracies were 82.124 - 109.017% and 85.292 - 104.131%, respectively. The APTES-GA probe displayed an excellent shelf-life of evaluation and can be stored at 4 ºC and -18 ºC for up to 6 weeks without a decrease in performance. The proposed method was applied to detect hydrogen peroxide in antiseptic commercial products. The results agreed with those from TiOSO4 spectrophotometry which was used as a reference method. Overall, the device is simple, rapid, cost-effective, portable, disposable, and suitable for onsite screening.