Preparation and Characteristics of Rat Anti-1,3,5-Trinitroperhydro-1,3,5-Triazine (RDX) Monoclonal Antibody and Detection of RDX Using Surface Plasmon Resonance Immunosensor

Abstract

In this paper, we develop a method of detecting 1,3,5-trinitroperhydro-1,3,5-triazine [research department explosive (RDX)]. RDX is one of the main components of plastic explosives. Initially, we prepare an anti-RDX monoclonal antibody that specifically binds to RDX. The antibody is prepared from hybridoma cells that are prepared by the iliac lymph node method. The dissociation constant of the antibody against RDX is estimated to be 9.6 nM from the results of indirect competitive enzyme-linked immunosorbent assay. We fabricate a sensor chip on which RDX analogues are immobilized through a self-assembled monolayer with oligo(ethylene glycol) chains. High reliability and low false recognition rate are particularly required for sensors used for detecting explosives. Therefore, the nonspecific adsorption of the fabricated sensor chip is evaluated to confirm whether the sensor chip inhibits this nonspecific adsorption. The response characteristics of the prepared antibody against RDX are examined by indirect competitive assay. Under an incubation time of 0 min in the indirect competitive assay, a detection limit of 40 ppt is realized at a sample injection duration of 6 min.

A field-deployed surface plasmon resonance (SPR) sensor for RDX quantification in environmental waters

“…These analytical figures compared well to other RDX sensors. For example, fluorescent sensors were able to detect 15 ppb (75 nM) 8 , in the mM range 13 and 3 pM 9 , electrochemical sensors detected 120 ppb (600 nM) 7 and other SPR sensors detected 12 fM 22 and 0.04 ppb (0.2 nM) 21 . Lastly, we have evaluated the use of a normalized calibration curve, to mitigate any potential fluctuation of the absolute response from different lots of the SPR sensors.…”

“…SPR sensors have been reported to meet this requirement for RDX monitoring in water with sub-ppb limits of detection, using sensing schemes based on competitive sensing involving an antibody 21 and based on a molecularly imprinted polymer (MIP) 22 . The MIP-based sensing scheme is especially attractive for environmental sensing technologies due to the stability of MIPs in environmental conditions and to the simplicity of the sensing scheme.…”

Modeling of Detection Limit for Competitive Immunoassay Using Surface Plasmon Resonance Sensor

“…The proposed mathematical model seems to be valid for general immunoassays using other antibody-antigen interactions by fitting four coefficients, k a , k b , k c , and K. In addition to TNT, immunoassays for other explosives, cyclotrimethylen-trinitramine (RDX) and triacetone triperoxide (TATP), have been reported. (29)(30)(31)(32) Elaboration of the detection using our theoretical model is expected to improve these assays.…”

Towards an Electronic Dog Nose: Surface Plasmon Resonance Immunosensor for Security and Safety

“…TNT-like compounds have aromatic rings and nitro functional groups and the antibody shows very low cross-reactivities to them. We have tried to develop antibodies against explosives [ 11 – 16 ]. However, we have consistently used the commercial antibody to compare newly modified sensor surfaces for detection of TNT.…”

“…Binding percentage, i.e. , the ratio of Δθ 1 to Δθ 0 , was used as a parameter for evaluation [ 16 ]. An incubation time (binding time in a tube without pump flow) of 15–20 min to allow the reaction between the antibody and antigen (target substance) to occur is normally carried out before measurement.…”