Weak-cooperative binding of a long single-stranded DNA chain on a surface.

Binding gene-wide single-stranded nucleic acids to surface-immobilized complementary probes is an important but challenging process for biophysical studies and diagnostic applications. The challenge comes from the conformational dynamics of the long chain that affects its accessibility and weakens its hybridization to the probes. We investigated the binding of bacteriophage genome M13mp18 on several different 20-mer probes immobilized on the surface of a multi-spot, label-free biosensor, and observed that only a few of them display strong binding capability with dissociation constant as low as 10 pM.

Serum antibody fingerprinting of SARS-CoV-2 variants in infected and vaccinated subjects by label-free microarray biosensor.

Both viral infection and vaccination affect the antibody repertoire of a person. Here, we demonstrate that the analysis of serum antibodies generates information not only on the virus type that caused the infection but also on the specific virus variant. We developed a rapid multiplex assay providing a fingerprint of serum antibodies against five different SARS-CoV-2 variants based on a microarray of virus antigens immobilized on the surface of a label-free reflectometric biosensor.

Fetal Myocarditis Associated With Maternal SARS-CoV-2 Infection.

We report the first case of significant fetal myocardial involvement associated with maternal SARS-CoV-2 infection, in which restoration of cardiac function at birth was noted. The demonstration of previous infection was supported by the quantification of humoral response in child and mother, in particular the presence of anti-N antibodies and through the detection of specific antibodies against the BA.4/5 variant.

Digital Detection of Single Virus Particles by Multi-Spot, Label-Free Imaging Biosensor on Anti-Reflective Glass.

Rapid detection of whole virus particles in biological or environmental samples represents an unmet need for the containment of infectious diseases. Here, an optical device enabling the enumeration of single virion particles binding on antibody or aptamers immobilized on a surface with anti-reflective coating is described. In this regime, nanoparticles adhering to the sensor surface provide localized contributions to the reflected field that become detectable because of their mixing with the interfering waves in the reflection direction.

Optimization of Ga production at an 18 MeV medical cyclotron with solid targets by means of cross-section measurement of Ga, Ga and Ga.

The future development of personalized nuclear medicine relies on the availability of novel medical radionuclides. In particular, radiometals are attracting considerable interest since they can be used to label both proteins and peptides. Among them, the β-emitter Ga is widely used in nuclear medicine for positron emission tomography (PET).