Multiplexed Instrument-Free Bar-Chart SpinChip Integrated with Nanoparticle-Mediated Magnetic Aptasensors for Visual Quantitative Detection of Multiple Pathogens

Abstract

A portable multiplexed bar-chart SpinChip (MB-SpinChip) integrated with nanoparticle-mediated magnetic aptasensors was developed for visual quantitative instrument-free detection of multiple pathogens. This versatile multiplexed SpinChip combines aptamer-specific recognition and nanoparticle-catalyzed pressure amplification to achieve a sample-to-answer output for sensitive point-of-care testing (POCT). This is the first report of pathogen detection using a volumetric bar-chart chip, and it is also the first bar-chart chip using a "spinning" mechanism to achieve multiplexed bar-chart detection. Additionally, the introduction of the spin unit not only enabled convenient sample introduction from one inlet to multiple separate channels in the multiplexed detection, but also elegantly solved the pressure cross-interference problem in the multiplexed volumetric bar-chart chip. This user-friendly MB-SpinChip allows visual quantitative detection of multiple pathogens simultaneously with high sensitivity but without utilizing any specialized instruments. Using this MB-SpinChip, three major foodborne pathogens including Salmonella enterica, Escherichia coli, and Listeria monocytogenes were specifically quantified in apple juice with limits of detection of about 10 CFU/mL. This MB-SpinChip with a bar-chart-based visual quantitative readout has great potential for the rapid simultaneous detection of various pathogens at the point of care and wide applications in food safety, environmental surveillance, and infectious disease diagnosis.

Development of Nanozymes for Food Quality and Safety Detection: Principles and Recent Applications

“…Beside the POD‐like nanozyme tags, Wei et al. () established a pressure‐based SpinChip for pathogen detection using the aptamer‐modified CAT‐like Pt NPs as a signal tag. All the above studies demonstrate the wide flexibility of nanozyme tags in a variety of detection methods.…”

“…In addition to common recognition elements, Liu, Han et al (2018) used POD-like MnO 2 NS conjugated with a specific nonapeptidefusion protein pVIII as a sandwich immunoassay tag for Vibrio parahaemolyticus (V. parahaemolyticus) detection. Beside the PODlike nanozyme tags, Wei et al (2018) established a pressure-based SpinChip for pathogen detection using the aptamer-modified CAT-like Pt NPs as a signal tag. All the above studies demonstrate the wide flexibility of nanozyme tags in a variety of detection methods.…”

Recent Progress of Nanozymes in the Detection of Pathogenic Microorganisms

“…With great advantages of tunability in activities, high stability as well as easy storage, noble-metal nanozymes show great potential in biosensing. [48][49][50][51][52][53][54][55][56][57][58][59][60] Numerous noble metal nanomaterials such as AuNPs, [48][49][50][51] Pt NPs, [52,53] PdPt, [54] PtAu, [55,56] PdCu, [57] FeCu NPs, [58] Pd@Pt NPs [59] and Au@Pt core/shell nanorods, [46,60] etc. have been widely studied for the detection of microbial pathogens.…”

“…[52,53] For instance, Yang's group [52] reported that PtNPs generated more than 400 times more O 2 per second than common catalase, resulting in much higher detection sensitivity. Recently, Wei and co-workers [53] prepared a multiplexed bar-chart SpinChip integrated with PtNP-mediated aptasensors for visual quantitative detection of three major foodborne pathogens, that is, Salmonella enterica, E. coli, and Listeria monocytogenes. As illustrated in Figure 2, the nanoparticle-mediated aptasensor was assembled by DNA hybridization between magnetic capture-beads-DNA and aptamer-DNA-PtNPs.…”

“…The pathogen concentration was proportional to the moving distance of the dyes, thereby realizing visual quantitative detection of pathogens. [53]…”