Silver Iodide-Chitosan Nanotag Induced Biocatalytic Precipitation for Self-Enhanced Ultrasensitive Photocathodic Immunosensor
Silver Iodide-Chitosan Nanotag Induced Biocatalytic Precipitation for Self-Enhanced Ultrasensitive Photocathodic Immunosensor
复制标题
碘化银-壳聚糖纳米标签诱导生物催化沉淀用于自增强超灵敏光电阴极免疫传感器。
DOI：
10.1021/acs.analchem.6b00297
复制
发表时间：
2016-06-07
影响因子：
7.4
通讯作者：
Lin, Yanyu
中科院分区：
文献类型：
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作者：
Gong, Lingshan;Dai, Hong;Lin, Yanyu
本工作首次将p型半导体银化壳聚糖纳米粒子（SICNP）作为过氧化物酶模拟物催化生物沉淀反应用于人白细胞介素-6（IL-6）的信号放大光电阴极免疫传感。将捕获的抗体固定在聚乙烯亚胺功能化的氮化碳（CN）基质上后，将SICNP作为光敏标签和过氧化物酶模拟物标记在二抗上，随后将其引入传感界面，通过抗原-抗体特异性识别构建夹心免疫分析平台。由于CN和AgI之间的能级匹配，SICNP的光电流强度和光稳定性显著提高，光生载流子的快速分离和传输。此外，有效的生物催化沉淀反应中的不溶性产物作为电子受体吸收光激发电子，导致SICNP的光电流信号再次大幅放大。在多重放大作用下，该传感器对IL-6具有良好的光电化学响应特性，线性范围为10（-6）~ 10 pg/mL，检测限为0.737 ag/mL。这项工作也进行了有前途的应用SICNP在开发一个超灵敏，成本效益高，无酶的生物标志物的光电阴极免疫传感器。
In this work, we first exposed that the application of p-type semiconductor, silver iodide-chitosan nanoparticle (SICNP), acted as peroxidase mimetic to catalyze the bioprecipitation reaction for signal-amplification photocathodic immunosensing of human interleukin-6 (IL-6). After immobilization of captured antibody onto a polyethylenimine-functionalized carbon nitride (CN) matrix, SICNPs as photoactive tags and peroxidase mimetics were labeled on secondary antibodies, which were subsequently introduced onto the sensing interface to construct sandwich immunoassay platform through antigen-antibody specific recognition. Due to the matched energy levels between CN and AgI, the photocurrent intensity and photostability of SICNP were dramatically improved with rapid separation and transportation of photogenerated carriers. Moreover, the insoluble product in effective biocatalytic precipitation reaction served as electron acceptor to scavenge the photoexcited electron, leading to great amplification of the photocurrent signal of SICNP again. With the help of multiamplification processes, this photocathodic immunosensor presented a turn-on photoelectrochemical performance for IL-6, which showed wide linear dynamic range from 10(-6) to 10 pg/mL with the ultralow detection limit of 0.737 ag/mL. This work also performed the promising application of SICNP in developing an ultrasensitive, cost-effective, and enzyme-free photocathodic immunosensor for biomarkers.