Sensitive detection of XXXX in tap water using TELISA.

@entity869 @entity12472 @entity15 @entity10664
UNASSIGNED: A highly sensitive flow injection analysis (FIA)-based thermal enzyme-linked immunoassay, TELISA, was developed for the rapid detection of @entity12472 ( @entity10664 ) in tap water. @entity10664 and b-lactamase-labeled @entity10664 were employed in a competitive immunoassay using a monoclonal antibody (mAb). After the off-column liquid-phase competition, the mAb was captured on the Protein G Sepharose    4 Fast Flow (PGSFF) column support material. Injected b-lactamase substrate @entity869 was degraded by the column-bound @entity10664 -b-lactamase, generating a detectable heat signal. Several assay parameters were optimized, including substrate concentration, flow rates and regeneration conditions, as well as the mAb and @entity10664 -b dilution ratios and concentrations. The assay linear range was 0.73-4.83 ng mL(-1) with a detection limit of 0.66 ng mL(-1). An entire heat signal requires 10 min for generation, and the cycle time is less than 40 min. The results were reproducible and stable. @entity10664 -spiked tap water samples exhibited a recovery rate of 103%-116%, which correlated with the UHPLC- @entity15 / @entity15 measurements. We attributed this significant increase in sensitivity over our previously published work to the following factors: (i) the capture of already-formed immune complexes on the column via immobilized Protein G, which eliminated chemical immobilization of the antibody; (ii) off-column preincubation allows the formation of immune complexes under nearly ideal conditions; and (iii) multiple buffers can be used to, in one case, enhance immune-complex formation and in the other to maximize enzymatic activity. Furthermore, the scheme creates a universal assay platform in which sensing is performed in the off-column incubation and detection after capture in the enzyme thermistor (ET) detector, which opens up the possibility of detecting any antigen for which antibodies were available.
