Gold nanorod biochip functionalization by antibody thiolation

Wang, Xuefeng; Mei, Zhong Lei; Wang, Yanyan; Tang, Liang

doi:10.1016/j.talanta.2014.11.023

Cited by 33 publications

(53 citation statements)

References 47 publications

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“…To functionalize GNRs with antibodies, 20 uL of Traut’s reagents (5mg/mL) are first added to 0.1 mL of anti-human IgG for 2 hrs [16]. Then 200 uL of GNR solution and 100 uL of SH-PEG (10 mg/mL) are added for incubation overnight (See Note 4).…”

Section: Methods (All Procedures Are Performed At Room Temperature Unmentioning

confidence: 99%

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Gold Nanorod Array Biochip for Label-Free, Multiplexed Biological Detection

Mei

Wang

Tang

2017

Biosensors and Biodetection

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Gold nanorod (GNR) based label-free sensing has been attractive due to its unique property of localized surface plasmon resonance (LSPR). Compared to bulk gold, the SPR of GNRs is more sensitive to the refractive index change caused by biological binding in the close proximity. Numerous studies have reported biological detection in solution based GNR probes. However, the biosensing has the intrinsic problems of fluctuating readings and short storage time due to nanoparticle aggregation. In contrast, a chip-based nanorod biosensor is a more robust and reliable platform. We have developed a nanoplasmonic biosensor in a chip format by immobilizing functionalized GNRs on a (3-mercaptopropyl)trimethoxysilane modified glass substrate. The covalent Au-S bond ensures a strong GNR deposition on the substrate. This biochip exhibits a high sensitivity and stability when exposed to physiological buffer with high ionic strength. Another advantage of GNR as optical transducer is its LSPR peak dependence on the aspect ratio, which provides an ideal multiplexed detection mechanism. GNRs of different sizes that exhibit distinct SPR peaks are combined and deposited on designated spots of a glass substrate. The spectral shift of the respective peaks upon the biological binding are monitored for simultaneous detection of specific analytes. Coupled with a microplate reader, this spatially resolved GNR array biochip results in a high-throughput assay of samples as well as multiplexed detection in each sample. Since most biological molecules such as antibodies and DNA can be linked to GNR using previously reported surface chemistry protocol, the label-free nanosensor demonstrated here is an effective tool for protein/DNA array analysis, especially for detection of disease biomarkers.

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Section: Methods (All Procedures Are Performed At Room Temperature Unmentioning

confidence: 99%

“…Given that antibodies have primary amine group, it is feasible to chemically modify antibody molecules with thiolation reagent to enable gold-antibody linkage [16]. Thus, these GNR-conjugated antibodies can work as biological receptors or bioprobes for detecting specific antigens.…”

Section: Introductionmentioning

confidence: 99%

Gold Nanorod Array Biochip for Label-Free, Multiplexed Biological Detection

Mei

Wang

Tang

2017

Biosensors and Biodetection

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“…Surface modification of GNRs with thiolated biological reporters was conducted following our previously reported protocol [18]. Briefly, 20 μL of Traunt’s reagent (5 mg/mL) were added to 100 μL of antibodies (i.e.…”

Section: Methodsmentioning

confidence: 99%

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

Mei

Dhanale

Gangaharan

et al. 2016

Talanta

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Magnetic nanoparticles (MNPs) are widely used in biosensing, bioimaging, and drug delivery. However, high quality superparamagnetic nanoparticles with uniform size were usually synthesized by thermal decomposition using organic solvents. To be suitable for biomedical applications, a facile and efficient water dispersion of iron oxide MNPs from solvent using an innovative agent, sodium oleate (NaOL) was described. The monodispersed MNPs (4 and 15 nm respectively) after transfer was biocompatible and stable at a broad temperature range (4–50°C) over months. More importantly, the NaOL coating allows for surface modification with selective functionality, rendering the aqueous MNPs highly customizable for biofunctionalization. Little effect on the superparamagnetism was observed after the water dispersion. To further evaluate its practical application in biosensing, custom MNPs were prepared for specific cardiac troponin I (cTnI) detection for myocardial infarction diagnosis. Specifically, gold nanorod (GNR) biochip was probed by the MNP-captured cTnI target analyte at varying concentrations. The signal transduction of the GNR sensor is based on the localized surface plasmon resonance (LSPR). The application of the MNPs resulted in a significant enhancement of the plasmonic response of the GNRs. As such, the MNP-mediated LSPR biosenisng showed a three times lower sensitivity as compared to the direct cTnI binding without functional MNPs. Computer simulation further elucidated that the enhancement was distance dependent between the MNP and the surface of the nanorod, which corroborated with experimental results.

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“…Tang and co-workers [268] successfully modified gold nanorods using thiolated antibody proteins. Simple, but unstable biomodification of gold nanoparticles involves physical adsorption, while stable linkage protocols require tedious and time-consuming chemical approaches.…”

Section: Traut's Reagentmentioning

confidence: 99%