Cheeveewattanagul N, Tien TT, Rijiravanich P, Surareungchai W, Somasundrum M. Photostable methylene blue-loaded silica particles used as label for immunosorbent assay of Salmonella Typhimurium.
Biotechnol Appl Biochem 2019;
66:842-849. [PMID:
31228877 DOI:
10.1002/bab.1796]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 06/21/2019] [Indexed: 12/27/2022]
Abstract
Salmonella Typhimurium is a major cause of food poisoning. To solve the limitations of the routine enzyme linked immunosorbent assay such as laborious assay procedure, lack of long-term enzyme stability, and insufficient sensitivity, we provided a non-enzymatic colorimetric immunosorbent assay platform to overcome these problems. The highly photostable redox dye particles was constructed by silica particles (diameter = 598 ± 14.4 nm) loaded with methylene blue (Si-MB) and applied to be a label for immunoassay of S. Typhimurium. The sandwich assay format involved incubation of an analyte in a microplate wells modified with monoclonal anti-Salmonella, followed by exposure to a polyclonal anti-Salmonella/Si-MB bioconjugate and then measurement of absorbance at 598 nm. The platform had an assay time of 20 min, could detect heat-killed Salmonella with a limit of detection of 48 CFU mL-1 , and gave good recoveries in milk. The labels could be stored at 4 °C for 70 days without any deterioration.
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