利用蛋白質保護之奈米金探針與側流層析技術應用於視覺辨識之快速可攜式汞離子偵測器

Abstract

近年來研究報告指出，利用奈米金粒子之獨特光學性質，已發展出具高靈敏性、快速分析的汞離子偵測器。然而，這些樣品須在無鹽類水溶液下檢測，以避免奈米金探針受干擾聚集進而失去偵測能力，同時亦須仰賴紫外光-可見光分光儀及螢光光譜儀等儀器的輔助以達到定量分析之目的。因此我們開發出一套嶄新且簡易操作的汞離子濃度偵測技術：藉由包覆羧酸化蛋白質的奈米金探針即使在鹽類水溶液中仍保有良好分散性之技術，結合側流層析法達到不須仰賴複雜儀器及專業知識即可操作之系統來偵測水溶液中的汞離子。利用奈米金探針分別滯留在硝化纖維薄膜上之檢測區所產生帶狀紅色區域作為視覺辨識的訊號來源。相較於其他方法，此設計之拋棄式感測器兼具有低成本、方便使用，以及快速、靈敏、污染物定量之工具等優點，在未來汞離子分析的環保議題中將會被廣泛應用。

Recent progress in the laboratory has been a result of improvements in rapid analytical techniques and detection limits for sensing mercury ions (Hg2+) by using the unique optical property of gold nanoparticles (AuNPs). Unfortunately, the contaminated samples are only treated with aqueous solution in the cuvettes and must contain none of salts that could induce the AuNPs aggregation and losing the sensing abilities. Additionally, those experiment procedures for the analysis of metal ion should be operated by the assist of UV-Vis or fluorescence spectrophotometer. A new and simple method for determining the concentration of Hg2+ was developed. We designed the AuNP probes of carboxylic modified protein that could protect the AuNPs from aggregating even in the salinity solutions and employed the lateral flow assay to detect the Hg2+ without complicated instrumentations and technical expertise. The captured AuNP probes on the test zone and control zone of the sensor produced the characteristic red bands, enabling visual discrimination of Hg2+ concentrations. The disposable sensor thus provides a low-cost, convenient, rapid, sensitive, and quantitative tool for the detection of contaminated samples. The demand of Hg2+ analysis in environmental applications requires parallel analytical strategies; such a method with simplicity and rapidity will find wide use in the future.