A convenient and economical colorimetric chemo-sensor was developed for glutamic acid (Glu) detection in actual samples. The nanoscale sensor was synthesized by coating silver ions with sodium bis(2-ethylhexyl) sulfosuccinate (AOT). The sensor, exhibited color change from yellow to pink when cross linked with Glu molecules and showed strong quenched in peak at 426 nm with the appearance of another absorption peak between 490 nm and 620 nm. The interaction mechanism of Glu and AOT-AgNPs was discussed with sophisticated analytical techniques i.e. Visible spectroscopy, Fourier transform infrared (FTIR) spectroscopy, Atomic force microscopy (AFM), and Dynamic light scattering (DLS). The results suggested that Glu interacted with the spheres of AOT-AgNPs through non-covalent bonding and electrostatic attractions of RNH₃⁺ and COOH⁻ groups, which caused time dependent complexation. In this manner, rapid method having detection and quantification limits of 1.64 µM and 4.98 µM in between 0.1 µM and 200 µM was achieved. Furthermore, this technique exhibited high selectivity toward Glu over a range of amino acids, biological relevant metal ions and molecules. Moreover, Glu molecules were effectively detected in physiological fluids with satisfactory recoveries in acceptable limit. Hence, this research offers an on-site colorimetric detection for Glu under easy operational conditions for vitro/non-invasive analyses.

开发了一种方便，经济的比色化学传感器，用于实际样品中的谷氨酸（Glu）检测。通过用双（2-乙基己基）磺基琥珀酸钠（AOT）涂覆银离子来合成纳米级传感器。该传感器与Glu分子交联时，颜色从黄色变为粉红色，并且在426 nm处出现强烈的猝灭峰，并出现了另一个在490 nm至620 nm之间的吸收峰。Glu和AOT-AgNPs的相互作用机理通过复杂的分析技术进行了讨论，即可见光谱，傅里叶变换红外（FTIR）光谱，原子力显微镜（AFM）和动态光散射（DLS）。结果表明，Glu通过RNH ₃ ⁺和COOH-的非共价键合和静电吸引作用与AOT-AgNPs球相互作用^。组，这导致时间依赖性的复杂化。以这种方式，可以实现检测和定量限在0.1 µM和200 µM之间的1.64 µM和4.98 µM的快速方法。此外，该技术对多种氨基酸，生物学相关的金属离子和分子具有对Glu的高选择性。此外，可以在生理液中有效检测到Glu分子，并在可接受的限度内具有令人满意的回收率。因此，这项研究为体外/非侵入性分析的简便操作条件下的Glu提供了现场比色检测。