Litluechai Arpaporn, Prompa Arreerat, Uppachai Pikaned, Jarernboon Wirat, Butwong Nutthaya, Mukdasai Siriboon
Materials Chemistry Research Center, Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Khon Kaen University Khon Kaen 40002 Thailand.
Department of Applied Physics, Faculty of Engineering, Rajamangala University of Technology Isan Khon Kaen Campus Khon Kaen 40000 Thailand.
RSC Adv. 2024 Oct 10;14(44):32101-32108. doi: 10.1039/d4ra03983a. eCollection 2024 Oct 9.
The cadmium ion (Cd) is highly poisonous and nondegradable and easily bioaccumulates through the food chain. Therefore, it is crucial to develop cost-effective chemical sensors for Cd with fast response time, high selectivity, and very low detection limits. In this study, a colorimetric sensor for the determination of Cd was fabricated by modifying silica sol with dodecyltrimethylammonium bromide (DTAB) and dithizone (DZ). Cd formed a complex with DZ, changing the solution color immediately from purple to orange prior to detection using ultraviolet-visible spectrophotometry and a customized Cd analyzer for the precipitate. Under the optimum conditions, the developed Cd sensor had a linear range of 0.01-0.25 mg L, a low limit of detection of 5.0 μg L, and outstanding repeatability. This sensor also showed good precision, with the relative standard deviations of less than 2.59% and 3.24% for the intra- and inter-day data, respectively. The proposed colorimetric method was successfully applied to determine Cd in environmental water samples, and the results were comparable to those obtained using standard atomic absorption spectrometry. Moreover, quantitative analysis was conducted using the customized Cd analyzer to estimate the color intensity change, without requiring sophisticated scientific instruments. This colorimetric sensor can be used for the portable, cost-effective, and rapid on-site detection of Cd in environmental water samples.
镉离子（Cd）具有高毒性且不可降解，容易通过食物链进行生物累积。因此，开发具有快速响应时间、高选择性和极低检测限的经济高效的镉化学传感器至关重要。在本研究中，通过用十二烷基三甲基溴化铵（DTAB）和双硫腙（DZ）修饰硅溶胶，制备了一种用于测定镉的比色传感器。镉与DZ形成络合物，在使用紫外可见分光光度法和定制的镉分析仪对沉淀物进行检测之前，溶液颜色立即从紫色变为橙色。在最佳条件下，所开发的镉传感器线性范围为0.01 - 0.25 mg/L，检测下限低至5.0 μg/L，且具有出色的重复性。该传感器还具有良好的精密度，日内和日间数据的相对标准偏差分别小于2.59%和3.24%。所提出的比色法成功应用于环境水样中镉的测定，结果与使用标准原子吸收光谱法获得的结果相当。此外，使用定制的镉分析仪进行定量分析以估计颜色强度变化，无需复杂的科学仪器。这种比色传感器可用于环境水样中镉的便携式、经济高效且快速的现场检测。
