Ultrasensitive Protein Concentration Detection on a Micro/Nanofluidic Enrichment Chip Using Fluorescence Quenching
Ultrasensitive Protein Concentration Detection on a Micro/Nanofluidic Enrichment Chip Using Fluorescence Quenching
复制标题
使用荧光淬灭在微/纳流体富集芯片上进行超灵敏蛋白质浓度检测
DOI：
10.1021/acsami.5b00383
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发表时间：
2015-04-01
影响因子：
9.5
通讯作者：
Xia, Xing-Hua
中科院分区：
文献类型：
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作者：
Wang, Chen;Shi, Yi;Xia, Xing-Hua
微/纳流体富集装置结合福斯特共振能量转移（FRET）技术已被开发用于痕量蛋白质的灵敏检测。在这种方法中，样品蛋白质首先被吸附在金纳米颗粒（AuNP）上以占据AuNP表面的一部分。然后，添加染料标记的蛋白质，其吸附到AuNP表面的残余活性位点，使AuNP表面充满蛋白质分子。未吸附的染料标记的蛋白质在系统中保持游离状态。保持固定量的染料标记的蛋白质，高浓度的样品蛋白质导致更多的游离染料标记的蛋白质分子保留在系统中，从而产生更大的光致发光信号。在电场的作用下，游离的染料标记的蛋白质分子可以被有效地富集在微/纳流控芯片的纳米通道前，这极大地放大了光致发光的幅度，提高了检测灵敏度。作为示范，牛血清白蛋白（BSA）和异硫氰酸荧光素标记的狗血清白蛋白（FITC-DSA）分别用作样品和荧光蛋白。使用所提出的策略，可以实现低至2.5 pg/mL的BSA的检测限，这比大多数敏感的商业蛋白质定量方法中报道的最低值低10（3）倍以上。
A micro/nanofluidic enrichment device combined with the Forster resonance energy transfer (FRET) technique has been developed for sensitive detection of trace quantities of protein. In this approach, sample protein is first adsorbed on gold nanoparticles (AuNPs) to occupy part of the AuNP surface. Then, dye-labeled protein is added, which adsorbs to the residual active sites of the AuNP surface, saturating the AuNP surface with protein molecules. The unadsorbed dye-labeled protein remains in a free state in the system. Keeping a fixed amount of dye-labeled protein, a high concentration of sample protein leads to more free dye-labeled protein molecules remaining in the system, and thus a larger photoluminescence signal. Under the action of an electric field, the free dye-labeled protein molecules can be efficiently enriched in front of the nanochannel of a micro/nanofluidic chip, which greatly amplifies the magnitude of the photoluminescence and improves the detection sensitivity. As a demonstration, bovine serum albumin (BSA) and fluorescein isothiocyanate-labeled dog serum albumin (FITC-DSA) are used as sample and fluorescent proteins, respectively. Using the proposed strategy, a detection limit of BSA as low as 2.5 pg/mL can be achieved, which is more than 10(3) times lower than the reported minimums in most sensitive commercial protein quantification methods.