A triple functional sensing chip for rapid detection of pathogenicListeria monocytogenes

Abstract

Here a triple functional sensing chip was created for L. monocytogenes detection by integrating three biomarkers (Listeriolysin O (LLO) at protein level, hly gene at genetic level, and acetoin at metabolic level). Liposome encapsulated catechol was used for LLO detection via LLO pore-forming ability. hly gene was specifically captured by using a thiolated capture probe on nanoporous gold (NPG). As an electroactive label, methylene blue was embedded in double-stranded structures to generate an electrochemical signal for hly detection. Combined with the electrocatalysis of NADH by NPG, the acetoin detection was achieved by measuring the consumption of NADH as a cofactor under acetoin reductase catalysis. Importantly, the L. monocytogenes detection results obtained by detecting three biomarkers using the chip can be mutually verified, which reduces the probability of false positives based on a single marker. Moreover, the detection time was reduced to about 90 min, making it a rapid and reliable tool for L. monocytogenes detection.

Design and 3D printing of an electrochemical sensor for Listeria monocytogenes detection based on loop mediated isothermal amplification

“…The detection of all the serotypes involved with foodborne listeriosis significantly improves the results reported by other authors for different transduction systems and sensor platforms. All of them probed to detect only one serotype of L. monocytogenes [ 52 , 53 , 54 , 55 , 56 ]. Otherwise, this primer set did not detect DNA from any of the non-monocytogenes Listeria spp.…”

Advanced Signal-Amplification Strategies for Paper-Based Analytical Devices: A Comprehensive Review

“…The moist paper was then immersed in a solution containing AuNPs. The colorimetric change elicited by AuNP aggregation in the presence of LLO enables LLO detection from as little as 12.9 µg mL −1 in PBS and 19.5 µg mL −1 in spiked human serum within 5 min, for an 18-fold enhancement in sensitivity compared to other liposome-based LLO detection assays [ 54 ]. An alternative way to prepare AuNP aggregates is based on a high concentration of salt in the reaction solution.…”