Detsri, Ekarat
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Item type:Publication, Aggregated gallic acid-modified platinum nanoparticles as colorimetric sensor for tannic acid detection in beverages based on displacement phenomenon(2024-10-01); ; A new colorimetric assay for the rapid detection of tannic acid in beverage samples based on displacement phenomenon of aggregated gallic acid-modified platinum nanoparticles is developed for the first time. PtNPs were functionalized with gallic acid, promoting the formation of the green-hued aggregated nanoparticles. While colorimetry offers a rapid method for identifying tannic acid, challenges remain in sensitivity and accuracy of detection on the PtNPs colorimetric probe, particularly in the presence of anthocyanin interferences. To address this, we developed a sample preparation method to degrade anthocyanin in beverages. Tannic acid was easily displaced onto the gallic acid-coated PtNPs surfaces, causing dispersion and resulting in a visible color change from green to orange − brown. Under the optimal conditions, the colorimetric sensor exhibited a linear response in the range of 1 − 2,000 µmol/L (R<sup>2</sup> = 0.9991). The limit of detection (LOD) and the limit of quantification (LOQ) were found at 0.02 and 0.09 µmol/L, respectively. The proposed sensor expressed superior selectivity over other interfering substances and demonstrated excellent precision with a relative standard deviation (RSD) of 1.00 %−3.36 %. More importantly, recoveries ranging from 95.0 − 104.7 % were obtained, indicating the capability of proposed colorimetric sensor to detect tannic acid rapidly and accurately in real beverage samples. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A new colorimetric method for determination of formaldehyde in sea food based on anti-aggregation of gold nanoparticles(2022-12-01); A new colorimetric method based on anti-aggregation of gold nanoparticles (AuNPs) in the presence of melamine for sensitive and selective determination of formaldehyde was developed. The citrate capped AuNPs was synthesized by Turkevich method. A certain concentration of melamine is responsible for color change of AuNPs from red to purple. The surface plasmon resonance peak was shifted from 520 to 640 nm. In the presence of formaldehyde, the reaction between melamine and formaldehyde to form methylol melamine was occurred, which resulted in the decreasing of aggregation of AuNPs. Based on the anti-aggregation mechanism, formaldehyde can be detected by observing the color change of AuNPs solution containing melamine, which was monitored by UV–visible spectrophotometer. Calibration curve plotted between absorbance ratio (A640/A520) and formaldehyde concentration was made with linearity of 0 – 2000 µg L<sup>−1</sup>. The limit of detection and the limit of quantitation were found at 26.0 µg L<sup>−1</sup> and 88.0 µg L<sup>−1</sup>, respectively. The method also provided high accuracy (%recovery in range 97.3 – 104%) and high precision (%RSD < 5.6). - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Highly sensitive and selective colorimetric sensor of mercury (II) based on layer–by–layer deposition of gold/silver bimetallic nanoparticles(2020-10-01); ; A new colorimetric sensor based on gold/silver bimetallic nanoparticles (Au–Ag BNPs) for the sensitive and selective detection of mercury (II) was developed. Gold nanoparticles (AuNPs) were synthesized by Turkevich method. The surface modification of AuNPs was modified by the layer–by–layer technique using poly(diallyl dimethylammonium chloride) which provided positively charged of AuNPs. Negatively charged silver nanoparticles (AgNPs) were synthesized by chemical reduction using poly(4–styrenesulfonic acid–co–maleic acid) as the stabilizing agent. The layer–by–layer assembly deposition technique was used to prepare Au–Ag BNPs of positively and negatively charged of AuNPs and AgNPs, respectively. The synthesized Au–Ag BNPs were characterized by a UV-visible spectrophotometer, zeta potential analyzer, FT–IR, TEM, XRD, and EDX. The Au–Ag BNPs sensor was able to detect mercury (II) in aqueous solution, visibly changing from brownish–orange to purple. The linear relationships of the UV-visible spectrometry demonstrate that the Au–Ag BNPs-based colorimetric sensor can be used for the quantitative analysis of mercury (II) in the range of 0.5–80 mg L<sup>−1</sup>, with the correlation coefficient, r<sup>2</sup> = 0.9818. The limit of detection (LOD) of mercury (II) was found to be 0.526 + 0.001 mg L<sup>−1</sup>. The BNPs is also verified to have a good practical applicability for mercury (II) detection in the real samples.