Development of a High-Efficiency Immunomagnetic Enrichment Method for Detection of Human Norovirus via PAMAM Dendrimer/SA-Biotin Mediated Cascade-Amplification

Sensitivity-enhanced hydrogel digital RT-LAMP with in situ enrichment and interfacial reaction for norovirus quantification in food and water

Low levels of human norovirus (HuNoV) in food and environment present challenges for nucleic acid detection. This study reported an evaporation-enhanced hydrogel digital reverse transcription loop-mediated isothermal amplification (HD RT-LAMP) with interfacial enzymatic reaction for sensitive HuNoV quantification in food and water. By drying samples on a chamber array chip, HuNoV particles were enriched in situ. The interfacial amplification of nucleic acid at the hydrogel-chip interface was triggered after coating HD RT-LAMP system. Nanoconfined spaces in hydrogels provided a simple and rapid "digital format" to quantify single virus within 15 min. Through in situ evaporation for enrichment, the sensitivity level was increased by 20 times. The universality of the sensitivity-enhanced assay was also verified using other bacteria and virus. Furthermore, a deep learning model and smartphone app were developed for automatic amplicon analysis. Multiple actual samples, including 3 lake waters, strawberry, tap water and drinking water, were in situ enriched and detected for norovirus quantification using the chamber arrays. Therefore, the sensitivity-enhanced HD RT-LAMP is an efficient assay for testing biological hazards in food safety monitoring and environmental surveillance.

FOF1-ATP synthase molecular motor biosensor for miRNA detection of colon cancer

AIMS

To establish a F_OF1-ATP synthase molecular motor biosensor to accurately identify colon cancer miRNAs.

MAIN METHODS

The F_OF1-ATP synthase molecular motor is extracted by fragmentation-centrifugation and connected to the colon cancer-specific miR-17 capture probe in the manner of the ε subunit-biotin-streptavidin-biotin system. Signal probes are designed for dual-signal characterization to increase detection accuracy. The F_OF1-ATPase rotation rate decreases when the signaling and capture probes are combined with the target miRNA, resulting in a decrease in ATP synthesis. miR-17 concentrations are determined by changes in ATP-mediated chemiluminescence intensity and signal probe-mediated OD_450nm.

KEY FINDINGS

The chemiluminescence intensity and OD_450nm show a good linear relationship with the miR-17 concentration in the range of 5 to 200 nmol L^-1 (R² = 0.9985, 0.9989). The colon cancer mouse model is established for the blood samples, and miR-17 in serum and RNA extracts is quantitatively determined using the constructed sensor.

SIGNIFICANCE

The results are consistent with colon cancer progression, and the low concentration of miR-17 detecting accuracy is comparable to the PCR assay. In conclusion, the developed method is a direct, rapid, and promising method for miRNA detection of colon cancer.