Graphene quantum dot coupled with gold nanoparticle based “off-on” fluorescent probe for sensitive and selective detection of L-cysteine
Graphene quantum dot coupled with gold nanoparticle based “off-on” fluorescent probe for sensitive and selective detection of L-cysteine
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DOI：
10.1007/s00604-016-1822-7
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发表时间：
2016-03
影响因子：
5.7
通讯作者：
Shan Huang;Lumin Wang;Chusheng Huang;Baoqing Hu;Wei Su;Qi Xiao
中科院分区：
文献类型：
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作者：
Shan Huang;Lumin Wang;Chusheng Huang;Baoqing Hu;Wei Su;Qi Xiao
作者报告说，石墨烯量子点（GQD）耦合到金纳米粒子（AuNP）是可行的L-半胱氨酸的“关-开”荧光探针。GQD的荧光通过荧光共振能量转移（FRET）被AuNP猝灭，并且这将GQD的蓝色荧光转变为“关闭”状态。荧光强度（在345 nm激发下测量）与0.15至2.16 nM范围内的AuNP浓度成反比，检测限为15 pM。GQD的荧光通过添加结合AuNP的L-半胱氨酸而转换回“开”状态，从而抑制淬灭。在1.0至4000 nM范围内，回收的荧光强度与L-半胱氨酸的浓度成正比，检测限为0.32 nM。对GQD和AuNP的浓度、pH值和反应时间进行了优化。该方法是选择性的，因为许多其他含硫醇的生物分子不干扰。将其应用于人体尿液和血浆样品中L-半胱氨酸的检测，得到了满意的结果。图形摘要石墨烯量子点偶联金纳米粒子是一种可行的“关-开”荧光探针，用于灵敏和选择性地测定L-半胱氨酸。
The authors report that graphene quantum dots (GQDs) coupled to gold nanoparticles (AuNPs) are viable “off-on” fluorescent probes for L-cysteine. The fluorescence of GQDs is quenched by AuNPs through fluorescence resonance energy transfer (FRET), and this shifts the blue fluorescence of the GQDs to an “off” status. Fluorescence intensity (measured under 345 nm excitation) is inversely proportional to the concentration of AuNPs in the 0.15 to 2.16 nM range, with a 15 pM detection limit. The fluorescence of the GQDs is converted back to an “on” status by adding L-cysteine which binds to the AuNPs and thereby suppresses quenching. The intensity of the recovered fluorescence is directly proportional to the concentration of L-cysteine in the 1.0 to 4000 nM range, and the limit of detection is 0.32 nM. The assay was optimized with respect to the concentration of GQDs and AuNPs, pH value, and reaction time. The method is selective in that many other thiol-containing biomolecules do not interfere. It was applied to the detection of L-cysteine in human urine and human plasma samples and gave satisfactory results.Graphical abstractGraphene quantum dot coupled to gold nanoparticle are a viable “off-on” fluorescent probe for sensitive and selective determination of L-cysteine.