摘要
A new biosensor platform was explored for detection of surfactant based on fluorescence changes from single strand DNA （ssDNA） and single-walled carbon nanotubes （SWNTs）. Thermodynamics assay was performed to value the stability of probe. The affinities of SWNT to five common surfactants （SDS, DBS, Triton X-100, Tween-20 and Tween-80） were investigated by real-time fluorescence method. The effects of Mg^2＋ and pH on the fluorescence intensity of self-assembled quenched sensor were performed. The fluorescent emission spectra were used to measure the responses of self-assembled quenched fluorescent of ssDNA/SWNTs to different concentration surfactant（Triton X-100）. The FAM-DNA wrapped SWNTs probe was stable in a wide temperature range （5 ℃ to 80℃）. The binding strength of surfactants and single-stranded DNA （ssDNA） on SWNTs surfaces was shown as follows： Triton X-100〉DBS〉Tween-20〉Tween-80〉ssDNA〉SDS, and the optimized reaction conditions included pH 7.4 and 10 mmol/L Mg2＋. The fluorescence of FAM-ssDNA wrapped SWNTs was proportionally recovered as a result of adding different concentrations of Triton X- 100, which realizes the quantitative detection of Triton X- 100.
研制一种基于单链DNA与单壁碳纳米管荧光变化的新型荧光探针用于表面活性剂物质的检测方法。考察了温度对探针稳定性的影响，通过观察实时荧光光谱变化来评估单壁碳纳米管与5种常见表面活性剂物质的亲和性，观察镁离子及pH对探针检测表面活性物质的影响，通过观察荧光发射光谱变化来考察加入不同浓度表面活性物质曲拉通X-100后荧光探针的荧光恢复情况。结果表明，在5～80℃的温度范围内，探针十分稳定；单壁碳纳米管与5种常见表面活性物质的亲和力由强至弱依次为曲拉通X．100、十二烷基苯磺酸钠、吐温-20、吐温-80、十二烷硫酸钠；荧光探针检测的最佳Mg抖浓度为10mmol／L，pH为7．4；当加入不同浓度的表面活性剂物质曲拉通X．100时，探针体系的荧光逐渐得到恢复。
基金
Projects (21075032, 21005026, 21135001) supported by the National Natural Science Foundation of China
Project (llJJ5012) supported by Hunan Provincial Natural Science Foundation, China
