In this paper, it was found that OliGreen emitted much stronger fluorescence in rigid T-Hg²⁺-T DNA structure than that in the presence of poly T. Thus, an OliGreen-responsive label-free fluorescent sensor was proposed for sensitive detection of organophosphorus pesticides (OPs) by constructing T-Hg²⁺-T DNA structure. OliGreen emits strong fluorescence in T-Hg²⁺-T structures. The rigid DNA structure of T-Hg²⁺-T is prone to be destroyed by thiocholine (TCh) that hydrolyzed by acetylcholinesterase (AChE) because of the high affinity of TCh with Hg²⁺. As a result, T-Hg²⁺-T DNA structure broke down and the fluorescence intensity of OliGreen decreased greatly. With the inhibition of AChE by OPs, fluorescence intensity of OliGreen remained strong because of the rigid T-Hg²⁺-T DNA structure. Thus, a “turn-on” fluorescent sensor which avoids synthesis of nanomaterials and complex label procedures is proposed based on the fluorescence intensity of OliGreen. DDVP were detected with a wide linear range from 0.005 to 25.0 ng/mL and the detection limit was 2.9 pg/mL, which is more sensitive than previously reported methods.

在本文中，发现OliGreen在刚性T-Hg ²⁺ -T DNA结构中发出的荧光要比多聚T存在时强得多。因此，提出了一种OliGreen响应型无标记荧光传感器，用于灵敏地检测T。通过构建T-Hg ²⁺ -T DNA结构来制备有机磷农药（OPs）。OliGreen在T-Hg ²⁺ -T结构中发出强荧光。T-Hg ²⁺ -T的刚性DNA结构容易被乙酰胆碱酯酶（AChE）水解的硫代胆碱（TCh）破坏，因为TCh与Hg ^2+的亲和力很高。结果，T-Hg ²⁺-T DNA结构断裂，OliGreen的荧光强度大大降低。随着OPs对AChE的抑制，由于刚性的T-Hg ²⁺ -T DNA结构，OliGreen的荧光强度仍然很强。因此，基于OliGreen的荧光强度，提出了一种“开启”式荧光传感器，该传感器避免了纳米材料的合成和复杂的标记程序。DDVP的线性范围从0.005到25.0 ng / mL，检出限为2.9 pg / mL，比以前报道的方法更灵敏。