Trace detection of explosives using a membrane-based displacement immunoassay

Present and future of surface plasmon resonance biosensors

“…Various optical methods have been exploited in biosensors including fluorescence spectroscopy [4], interferometry (reflectometric white light interferometry [5] and modal interferometry in optical waveguide structures [6]), spectroscopy of guided modes of optical waveguides (grating coupler [7] and resonant mirror [8]), and surface plasmon resonance (SPR) [9,10]. Fluorescence-based biosensors offer high sensitivity but, due to the use of labels, they require either multi-step detection protocols or delicately balanced affinities of interacting biomolecules for displacement assays, causing sensor cross-sensitivity to non-target analytes [11]. Sensors such as optical interferometers, grating coupler, resonant mirror, and SPR rely on the measurement of binding-induced refractive index changes and thus are label-free technologies.…”

Surface plasmon resonance immunosensor for highly sensitive detection of 2,4,6-trinitrotoluene

“…Several immunological formats such as fiberoptic biosensor, sol-gel entrapped assays, microcapillary, enzyme linked immunosorbant assay (ELISA), self-assembly etc., with different sensing principles have been reported for the detection of TNT and related nitroaromatic compounds. However, most of them involve multi-step and complicated sensor fabrication, labelling of the reagents and are less sensitive (Bakaltcheva et al, 1999;Green et al, 2002;Bowen et al, 2003;Altstein et al, 2001;Gauger et al, 2001;Rabbany et al, 2000). The present immunosensor is sim- ple and highly sensitive for the analysis of dissolved TNT.…”

Displacement Immunosensor Based on Surface Plasmon Resonance for Rapid and Highly Sensitive Detection of 2,4,6-Trinitrotoluene

“…Premixing of the antibody and antigen solutions is not required before measurement by displacement immunoassay (16) Figure 1 shows the principle of displacement immunoassay for detecting TNT in this study. When TNT-Ab is added to the TNT analogue immobilized on the sensor surface, the increase in SPR response is due to the binding of TNT-Ab to the immobilized TNT analogue.…”

“…(16,17) A higher sensitivity is also obtained using a combination of an immobilized antigen and a labeled antibody at a lower flow rate. (18) Therefore, the flow rate was fixed at 10 μl/min, which was lower than the default flow rate (20 μl/min) of BiacoreX.…”