Automated fiber optic biosensor for multiplexed immunoassays

The multianalyte capability of the RAPTOR, a rapid, automatic, and portable fiber optic fluorimeter, was demonstrated. Employing evanescent wave illumination an polystyrene fiber optic waveguides, the RAPTOR performed fluorescent immunoassays for Bacillus globigii spores, ovalbumin, Erwinia herbicola, and MS2 coliphage. During a 4-day laboratory trial assaying 144 blind samples, the RAPTOR demonstrated detection of 10(5) cfu/mL B. globigii, 10(7) cfu/mL. E. herbicola, and 10(9) pfu/mL MS2; ovalbumin detection was less favorable than expected due to sample degradation. Assays were completed in 10 min with no sample preprocessing. No false positives were identified. Antigen carryover between coupons was examined but was not found to elicit a notable response far any analytes, except B. globigii. Finally, assay results obtained after reagent and waveguides had completed 30 negative (buffer) cycles were compared with standard assay results achieved with fresh reagent and waveguides to determine whether antigen detection would decrease using cycled reagent or optical probes. Detection efficacy proved to be unaffected by the use of cycled versus fresh probes or reagent.