#analytical chemistry, #Cas12,  #CRISPR  biosensors, #strand displacement reaction

#analytical chemistry, #Cas12,  #CRISPR  biosensors, #strand displacement reaction

Electrogenerated chemiluminescence from luminol-labelled microbeads triggered by in situ generation of hydrogen peroxide

A. Fiorani, C. Ignazio Santo, K. Sakanoue, D. Calabria, M. Mirasoli, F. Paolucci, G. Valenti, Y. Einaga

We developed a sensing strategy that mimics the bead-based electrogenerated chemiluminescence immunoassay. However, instead of the most common metal complexes, such as Ru or Ir, the luminophore is luminol. The electrogenerated chemiluminescence of luminol was promoted by in situ electrochemical generation of hydrogen peroxide at a boron-doped diamond electrode. The electrochemical production of hydrogen peroxide was achieved in a carbonate solution by an oxidation reaction, while at the same time, microbeads labelled with luminol were deposited on the electrode surface. For the first time, we proved that was possible to obtain light emission from luminol without its direct oxidation at the electrode. This new emission mechanism is obtained at higher potentials than the usual luminol electrogenerated chemiluminescence at 0.3–0.5 V, in conjunction with hydrogen peroxide production on boron-doped diamond at around 2–2.5 V (vs Ag/AgCl).

#electrochemiluminescence,  #Microscopy, Electrode,  biosensors

#Cas12,  #CRISPR  biosensors, #strand displacement reaction

PAM-Engineered Toehold Switches as Input-Responsive Activators of CRISPR-Cas12a for Sensing Applications

N. Bagheri,    A. Chamorro,    A. Idili and  A. Porchetta

Toehold Switch DNA presenting a locked anti-PAM in the loop are designed to control Cas12a activity in response to different molecular  inputs.  The hairpin  to  duplex  reconfiguration  triggered  by  co-localization-based  displacement  reactions  provides  a means to control the accessibility of the PAM and as a consequence Cas12a activity. We demonstrate the rapid, one-pot detection of antibodies and small molecules with high sensitivity and specificity.

#Cas12,  #CRISPR  biosensors, #strand displacement reaction

Electrogenerated chemiluminescence at boron-doped diamond electrodes

A. Fiorani,    G. Valenti,    F. Paolucci and  Y. Einaga   

The paper presents Boron Doped Diamond as new electrode for Electrochemiluminescence:

Boron-Doped Diamond (BDD) as an electrode material for ECL which has complementary properties compared to the most common metals (e.g., Au or Pt) and carbon materials (e.g., glassy carbon, carbon nanotubes and graphene). Boron-doped diamond electrodes emerged as novel electrodes, gaining more and more interest from the electrochemical community for their peculiar characteristics such as a wide solvent window, low capacitance, resistance to fouling and mechanical robustness.