Selective detection of tricyclazole by optical technique using thiomalic acid–modified Au and Ag nanoparticle mixtures

Yu-Shu Pan^a, Tsunghsueh Wu^b, Cho-Chun Hu^c, Tai-Chia Chiu^c, Chen-Hao Yeh^d, and Yang-Wei Lin^a,*

^a Department of Chemistry, National Changhua University of Education, 1 Jin-De road, Changhua City, 50007, Taiwan

^b Department of Chemistry, University of Wisconsin-Platteville, 1 University Plaza, Platteville, Wisconsin, 53818-3099, USA

^c Department of Chemistry, National Taitung University, 369 sec. 2 University road, Taitung, 950309, Taiwan

^d Department of Materials Science and Engineering, Feng Chia University, 100, Wenhwa road, Taichung City, 40724, Taiwan

This study proposes the use of thiomalic acid–modified Au and Ag nanoparticle mixtures (TMA-Au/AgNP mixes) for the selective detection of tricyclazole. Upon the addition of tricyclazole, the color of TMA-Au/AgNP mixes solution changes from orange-red to lavender (red-shift). According to the density-functional theory calculations, tricyclazole-induced aggregation of TMA-Au/AgNP mixes through electron donor–acceptor interactions was proved. The sensitivity and selectivity of the proposed method are affected by the amount of TMA, volume ratio of TMA-AuNPs to TMA-AgNPs, pH value, and buffer concentration. The ratio of absorbance (A₆₅₄/A₅₂₀) of TMA-Au/AgNP mixes solution is proportional to the concentration of tricyclazole over the range 0.1–0.5 ppm with a linear correlation (R² = 0.948). Moreover, the limit of detection was estimated at 0.028 ppm. The practicality of TMA-Au/AgNP mixes was validated for the determination of tricyclazole concentration in real samples (spiked recovery was 97.5%–105.2%), demonstrating its advantages of simplicity, selectivity, and sensitivity.

Keywords: Aggregation; Electron donor–acceptor interactions; Pesticides; TMA-AuNPs; TMA-AgNPs

https://doi.org/10.38212/2224-6614.3450