Electrical Graphene Aptasensor for Ultra-Sensitive Detection of Anthrax Toxin with Amplified Signal Transduction
Electrical Graphene Aptasensor for Ultra-Sensitive Detection of Anthrax Toxin with Amplified Signal Transduction
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DOI：
10.1002/smll.201203245
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发表时间：
2013-10-11
期刊：
影响因子：
13.3
通讯作者：
Lee, Nae-Eung
中科院分区：
文献类型：
--
作者：
Kim, Duck-Jin;Park, Hae-Chul;Lee, Nae-Eung
基于化学衍生的石墨烯场效应晶体管 (FET) 平台的电适体传感器证明了在阿摩尔 (aM) 水平上检测炭疽毒素（保护性抗原 (PA)）。与抗体固定的 FET 相比，适配体固定 FET 中的适体探针与 PA 的亲和力更高，可显着提高检测限 (LOD)、动态范围和灵敏度。由于捕获的 PA 分子的增加，适体 FET 中的转导信号增强，导致作为灵敏度参数的电荷中性点 (V-g,V-min) 发生 30 mV/十倍频移，PA 浓度的动态范围在 12 aM (LOD) 和 120 fM 之间。二次适体缀合的金纳米颗粒（AuNPs-适体）获得了额外的信号增强，其具有适体/PA/适体-AuNPs的夹心结构，诱导石墨烯通道中电荷掺杂的增加，导致LOD降低至1.2 aM，同时V-g、V-min位移增加三倍。
Detection of the anthrax toxin, the protective antigen (PA), at the attomolar (aM) level is demonstrated by an electrical aptamer sensor based on a chemically derived graphene field-effect transistor (FET) platform. Higher affinity of the aptamer probes to PA in the aptamer-immobilized FET enables significant improvements in the limit of detection (LOD), dynamic range, and sensitivity compared to the antibody-immobilized FET. Transduction signal enhancement in the aptamer FET due to an increase in captured PA molecules results in a larger 30 mV/decade shift in the charge neutrality point (V-g,V-min) as a sensitivity parameter, with the dynamic range of the PA concentration between 12 aM (LOD) and 120 fM. An additional signal enhancement is obtained by the secondary aptamer-conjugated gold nanoparticles (AuNPs-aptamer), which have a sandwich structure of aptamer/PA/aptamer-AuNPs, induce an increase in charge-doping in the graphene channel, resulting in a reduction of the LOD to 1.2 aM with a three-fold increase in the V-g,V-min shift.