TdT combined with Cas14a for the electrochemical biosensing of NPC-derived exosomes.

In this work, the electrochemical biosensor based on the subtle combination of terminal deoxynucleotidyl transferase (TdT), CRISPR/Cas14a, and magnetic nanoparticles (MNPs) was developed for the detection of nasopharyngeal carcinoma (NPC)-derived exosomes. Due to the synergistic effect of the following factors: the powerful elongation capacity of TdT for single-stranded DNA (ssDNA) with 3-hydroxy terminus, the outstanding trans-cleavage ability of CRISPR/Cas14a specifcally activated by the crRNA binding to target DNA, and the excellent separation ability of MNPs, the developed electrochemical biosensor exhibited high sensitivity for the detection of NPC-derived exosome, with a linear range from 6.0 × 10 ∼ 1.

The fluorescent aptasensor based on CRISPR-Cas12a combined with TdT for highly sensitive detection of cocaine.

Ultrasensitive and specific detection of cocaine is of great significance for monitoring cocaine abuse. Herein, a fluorescent aptasensor via coupling CRISPR-Cas12a, with magnetic nanoparticles (MNPs), split-aptamer, and terminal deoxynucleotidyl transferase (TdT), was developed for the detection of cocaine. In short, the complete cocaine aptamer is split into two parts, one is modified on magnetic nanoparticles (MNPs) and the other is free.

Correction: Ultrasensitive fluorescent aptasensor for CRP detection based on the RNase H assisted DNA recycling signal amplification strategy.

[This corrects the article DOI: 10.1039/C9RA01352K.].

A highly sensitive electrochemical aptasensor for vascular endothelial growth factor detection based on toehold-mediated strand displacement reaction.

An electrochemical aptasensor with high sensitivity, specificity, and good intra-day reproducibility is reported to meet the detection needs of vascular endothelial growth factor (VEGF). The toehold-mediated strand displacement recycling amplification and VEGF aptamer are integrated in the biosensor. The probe A is hybridized with the VEGF aptamer to form the probe A-aptamer complex.

[Extraction of exosome by gel electrophoresis microfluidic chip and determination of miRNA-21 in exosome of human plasma].

We developed a high-efficiency microfluidic chip for extracting exosomes from human plasma. We collected peripheral blood from normal human, designed and fabricated a microfluidic chip based on nanoporous membrane and agarose gel electrophoresis to isolate exosomes. The extracted exosomes were characterized by transmission electron microscopy, nanosight and Western blotting, the morphology, concentration and particle size of exosomes were identified and analyzed.

Ultrasensitive fluorescent aptasensor for CRP detection based on the RNase H assisted DNA recycling signal amplification strategy.

An aptamer-based method for the ultrasensitive fluorescence detection of C-reactive protein (CRP) was developed using the ribonuclease H (RNase H) assisted DNA recycling signal amplification strategy. In this assay, CRP can specifically bind to the aptamer of CRP and the DNA chain of P1 is released from the aptamer/P1 (Ap/P1) complexes. After the addition of the fluorescence labeled (5-FAM) RNA, P1 hybridizes with fluorescence labeled RNA to form a P1/RNA double strand.