Multiplexed gold nanorod array biochip for multi-sample analysis

Abstract

Optical transduction of biological bindings based on localized surface plasmon resonance (LSPR) of gold nanorods (GNRs) is attractive for label-free biosensing. The aspect ratio (AR) dependence of LSPR band maxima inherently provides an ideal multiplex mechanism. GNRs of selected sizes can be combined to ensure distinct plasmon peaks in absorption spectrum. Monitoring the spectral shift at the dedicated peaks allows for simultaneous detection of the specific analyte. Here, we first transformed the GNR’s multiplexed biosensing capability to a robust chip-based format. Specifically, nanorods of AR 2.6 and 4.5 were assembled onto thiol-terminated substrates, followed by functionalization of respective antibodies to construct a GNR multiplex biochip. As a model system, concentrations of human IgG and rabbit IgG were simultaneously measured by correlating red-shifts at distinct resonance peaks caused by specific target binding. The calibration curves exhibited linear relationship between the spectral shift and analyte amount. The sensing performance in multi-analyte mode correlated nicely with those for single analyte detection with minimal cross-reactivity. Moreover, mixed GNRs can be deposited in controllable array pattern on the glass chip to analyze numerous samples at the same time. Each GNRs dot functioned independently as a multiplexed plamonic sensor. Coupled with microplate reader, this GNR nanoarray chip can potentially result in large scale assay of samples concurrently while for each sample, a multi-analyte detection simultaneously if desired. The concept shown in this work is simple and versatile that will definitely be a new paradigm in high-throughput protein biochip development in the era of nano-biosensing.

Water dispersion of magnetic nanoparticles with selective Biofunctionality for enhanced plasmonic biosensing

“…To construct a LSPR nanoarray biosensor, functional GNR probes were effectively immobilized onto a glass substrate in a chip-based format [19]. Briefly, the glass substrates were first treated with MPTMS solution (10% in ethanol) to enrich the surface with thiol groups.…”

Switchable bioelectronics

“…The last few decades have witnessed the transformation of these lab-scale bioelectronic interfaces into real commercial bioelectronic devices (Katz 2014;Zhirnov and Cavin 2015). To date, several types of bio-device have contributed towards practical realisation of this vision, such as the amperometric blood glucose biosensor (Cass et al 1984;Newman and Turner 2005), real-time affinity sensors (Daniels and Pourmand 2007;Hunt and Armani 2010;Luo and Davis 2013), sensors based on surface plasmon resonance (Lee et al 2015;Liedberg et al 1983;Wang and Tang 2015), and field-effect devices (Lundstrom and Winquist 1987;Shen et al 2014). There have, of course, been many important challenges and technical hurdles in the research and development of bioelectronic devices, whether at the lab-scale or in commercial applications.…”

Double Plasmon Resonance Nanostructured Silver Coatings with Tunable Properties

“…This may be achieved by numerous techniques that employ both top-down and bottom-up preparation strategies, including sputtering or cluster beam deposition [15][16][17]. In addition, today, considerable attention is given to materials that exhibit multiple LSPR peaks, as they may trigger the development of multifunctional platforms that will combine more detection techniques on a single platform or will enable to use multiple light sources operated at different wavelengths and to multiplex them [18,19]. Moreover, as already shown theoretically [20] and experimentally [21], the dual-LSPR materials offer strong field enhancements, both in the excitation and scattering wavelengths, which, in turn, may lead to the significant total enhancement of the detected SERS signal.…”