Heating promoted super sensitive electrochemical detection of p53 gene based on alkaline phosphatase and nicking endonuclease Nt.BstNBI-assisted target recycling amplification strategy at heated gold disk electrode.

An ultrasensitive electrochemical biosensor for detecting p53 gene was fabricated based on heated gold disk electrode coupling with endonuclease Nt.BstNBI-assisted target recycle amplification and alkaline phosphatase (ALP)-based electrocatalytic signal amplification. For biosensor assembling, biotinylated ssDNA capture probes were first immobilized on heated Au disk electrode (HAuDE), then combined with streptavidin-alkaline phosphatase (SA-ALP) by biotin-SA interaction.

Plasmonic Au nanocube enhanced SERS biosensor based on heated electrode and strand displacement amplification for highly sensitive detection of Dam methyltransferase activity.

In this work, a novel "turn-on" mode Au nanocubes (AuNCs) enhanced surface-enhanced Raman scattering (SERS) biosensing platform coupled with heated Au electrode (HAuE) and strand displacement amplification (SDA) strategy was proposed for highly sensitive detection of DNA adenine methylation (Dam) Methyltransferase (MTase) activity. The Dam MTase and DpnI enzyme activities were significantly increased by elevating the HAuE surface temperature, resulting in the rapid production of template DNA for later SDA. During the SDA process, the released single-stranded DNA (ssDNA) could be amplified exponentially, and its concentration was positively related to the Dam MTase activity.

AuNanostar@4-MBA@Au Core-Shell Nanostructure Coupled with Exonuclease III-Assisted Cycling Amplification for Ultrasensitive SERS Detection of Ochratoxin A.

The "turn-on" mode surface-enhanced Raman scattering (SERS) aptasensor for ultrasensitive ochratoxin A (OTA) detection was developed based on the SERS "hot spots" of AuNanostar@4-MBA@Au core-shell nanostructures (AuNS@4-MBA@Au) and exonuclease III (Exo III)-assisted target cycle amplification strategy. Compared with conventional gold nanoparticles, AuNS@4-MBA@Au provides a much higher SERS enhancement factor because AuNS exhibits a larger surface roughness and the lightning rod effect, as well as an excellent electromagnetic field between the AuNS core and the Au shell, which contribute to the superstrong SERS signal. Meanwhile, Exo III-assisted target cycle amplification can be used as an effective method for the further amplified detection of OTA.