Protein Microarrays with Carbon Nanotubes as Multi-Color Raman Labels

TL;DR

This paper introduces a highly sensitive, multiplexed protein detection method using functionalized carbon nanotubes as multi-color Raman labels, achieving detection sensitivity down to 1 femtomolar and demonstrating stability and specificity in complex biological samples.

Contribution

The study presents a novel application of carbon nanotubes as multi-color Raman labels for protein microarrays, significantly improving detection sensitivity and enabling multiplexed analysis.

Findings

Detection sensitivity down to 1 fM using SERS and SWNTs.

Successful detection of autoantibodies in human serum up to 10^7 dilution.

Demonstration of two-color multiplexed protein detection with isotope-labeled SWNTs.

Abstract

Detection of biomolecules is important in proteomics and clinical diagnosis and treatment of diseases. Here, we apply functionalized, macromolecular, single walled carbon nanotubes SWNTs as multi-color Raman labels to protein arrays for highly sensitive, multiplexed protein detection. Raman detection utilizes the sharp peaks of SWNTs with minimal background interference, affording a high signal to noise ratio needed for ultra-sensitive detection. Surface-enhanced Raman scattering SERS combined with the strong resonance Raman intensity of SWNTs, affords detection sensitivity down to 1 fM, a three order of magnitude improvement over most of reported fluorescence-based protein detections. We show that human autoantibodies to Proteinase 3 aPR3, a biomarker for the autoimmune disease Wegeners granulomatosis, is detected by Raman in human serum up to a 107 dilution. Moreover, SWNT Raman tags are stable against photobleaching and quenching, and by conjugating different antibodies to pure 12C and 13C SWNT isotopes, we demonstrate two-color SWNT Raman-based protein detection in a multiplexed fashion.