Tubular waveguide evanescent field absorption biosensor based on particle plasmon resonance for multiplex label-free detection.

A novel tubular waveguide particle plasmon resonance (TW-PPR) sensor is demonstrated for label-free biochemical detection. The sensor itself is a microchamber of a defined sample volume, a mechanical support for sensor coating, a waveguide to provide evanescent wave interrogation, and it can be easily extended to a multi-channel format. The sensor resolution is estimated to be 2.6×10(-6) RIU in measuring solutions of various refractive indices. The sensing system can perform multiple measurements simultaneously and its limit of detection for anti-DNP antibody and streptavidin is 1.2×10(-10) g/ml (0.55 pM) and 2.3×10(-10) g/ml (3.5 pM), respectively. Accurate determination of these analytes with known concentration spiked in artificial urine were examined and the bias is less than ±7%, supporting the utility of the device for analyte screening in more complex media. The TW-PPR sensor can be inexpensively fabricated and has a special niche for monitoring biomolecular interactions in real-time, hence it is ideally suitable for disposable uses, especially promising for convenient high-throughput biochemical sensing applications.