High Sensitivity Detection of Tumor Cells in Biological Samples using Multivalent Aptamer Strand Displacement Strategy

Monitoring the cell surface-expressed nucleolin facilitates early cancer diagnosis. Herein, we developed multivalent aptamer displacement strand duplex strategy on the cell membranes utilizing a multi-receptor co-recognition design for improving sensitivity...

Construction of a Au@MoS2 composite nanosheet biosensor for the ultrasensitive detection of a neurotransmitter and understanding of its mechanism based on DFT calculations

An electrochemical biosensor based on Au@MoS2 composite nanosheets was successfully prepared for the high-sensitivity detection of dopamine.

CRISPR/Cas12a-Based Assay for the Rapid and High-Sensitivity Detection of Streptococcus Agalactiae Colonization in Pregnant Women with Premature Rupture of Membrane

Background Streptococcus agalactiae or group B Streptococcus (GBS) is a leading infectious cause of neonatal morbidity and mortality. This study aims to establish a novel method, termed as the CRISPR-GBS assay, for the rapid and sensitive detection of GBS that is based on the clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated protein (Cas) system. Results The CRISPR-GBS assay detected GBS in the samples within 35 min. The limit of detection was as low as 5 copies/µL and showed no cross-reactivity with other microorganisms. The clinical performance was assessed using vaginal or cervical swab samples that were collected from 179 pregnant women with premature rupture of membrane. Compared with the culture-based matrix-assisted laser desorption ionization time-of-flight mass spectrometry method, the CRISPR-GBS assay demonstrated a sensitivity of 96.64% (144/149, 95% confidence interval [CI] = 92.39–98.56%) and a specificity of 100% (30/30, 95% CI = 88.65–100%). It also had a high concordance rate of 98.88% with the real-time fluorescence polymerase chain reaction assay. Conclusions The CRISPR-GBS assay can be used for rapid and high-sensitivity detection of GBS in a simple and cost-efficient manner; thus, it offers a novel method for intrapartum screening.

A Novel Photoelectrochemical Aptamer Sensor Based on CdTe Quantum Dots Enhancement and Exonuclease I-Assisted Signal Amplification for Listeria monocytogenes Detection

To achieve the rapid detection of Listeria monocytogenes, this study used aptamers for the original identification and built a photoelectrochemical aptamer sensor using exonuclease-assisted amplification. Tungsten trioxide (WO3) was used as a photosensitive material, was modified with gold nanoparticles to immobilize complementary DNA, and amplified the signal by means of the sensitization effect of CdTe quantum dots and the shearing effect of Exonuclease I (Exo I) to achieve high-sensitivity detection. This strategy had a detection limit of 45 CFU/mL in the concentration range of 1.3 × 101–1.3 × 107 CFU/mL. The construction strategy provides a new way to detect Listeria monocytogenes.