金纳米棒传感器对血清中模型分析物的等离子体检测。

Plasmonic detection of a model analyte in serum by a gold nanorod sensor.

作者信息

Marinakos Stella M, Chen Sihai, Chilkoti Ashutosh

机构信息

Department of Biomedical Engineering, Center for Biologically Inspired Materials and Material Systems, Duke University, Durham, North Carolina 27708, USA.

出版信息

Anal Chem. 2007 Jul 15;79(14):5278-83. doi: 10.1021/ac0706527. Epub 2007 Jun 14.

DOI:10.1021/ac0706527

PMID:17567106

Abstract

We describe the fabrication of a label-free, chip-based biosensor based on the localized surface plasmon resonance (LSPR) of gold nanorods. Gold nanorods were chemisorbed onto a mercaptosilane-modified glass substrate, followed by conjugation of biotin to the nanorods. Streptavidin binding to biotin was monitored by the wavelength shift of the LSPR peak in the UV-vis extinction spectrum of the immobilized gold nanorods due to the change in local refractive index at the gold nanorod surface induced by streptavidin binding. The limit of detection of the sensor is 0.005 microg/mL (94 pM) in PBS and 1 microg/mL (19 nM) in serum, and the dynamic range spans 94 pM to 0.19 microM. The advantages of the nanorod-based sensor over an LSPR sensor that we had previously fabricated from gold nanospheres (Nath, N.; Chilkoti, A. Anal. Chem. 2002, 74, 504-509; J. Fluoresc. 2004, 14, 377-389; Anal. Chem. 2004, 76, 5370-5378) are the significantly lower detection limit and the internal self-reference that the signal of the nanorod sensor provides based on the measurement of peak wavelength shift.

摘要

我们描述了一种基于金纳米棒的局域表面等离子体共振（LSPR）的无标记芯片式生物传感器的制备。金纳米棒通过化学吸附作用固定在巯基硅烷修饰的玻璃基板上，随后将生物素偶联到纳米棒上。由于链霉亲和素结合导致金纳米棒表面局部折射率发生变化，通过固定化金纳米棒的紫外 - 可见消光光谱中LSPR峰的波长移动来监测链霉亲和素与生物素的结合。该传感器在磷酸盐缓冲盐溶液（PBS）中的检测限为0.005μg/mL（94 pM），在血清中的检测限为1μg/mL（19 nM），动态范围为94 pM至0.19μM。与我们之前用金纳米球制备的LSPR传感器相比（Nath, N.; Chilkoti, A. Anal. Chem. 2002, 74, 504 - 509; J. Fluoresc. 2004, 14, 377 - 389; Anal. Chem. 2004, 76, 5370 - 5378），基于纳米棒的传感器的优势在于检测限显著降低，并且基于峰值波长移动的测量，纳米棒传感器的信号提供了内部自参考。