A facile method for urinary phenylalanine measurement on paper-based lab-on-chip for PKU therapy monitoring.

A miniaturized paper-based lab-on-chip (LoC) was developed for the facile measurement of urinary Phe (phenylalanine) level on PKU (Phenylketonuria) treated patient. This system permits the monitoring of Phe in a dynamic range concentration of 20-3000 µM.

Ionic strength-controlled hybridization and stability of hybrids of KRAS DNA single-nucleotides: A surface plasmon resonance study.

The discrimination of a fully matched, unlabeled KRAS wild-type (WT) (C-G) target sample with respect to three of the most frequent KRAS codon mutations (G12 S (C-A), G12 R (C-C), G12C (C-T)) was investigated using an optimized detection strategy involving surface plasmon resonance (SPR), based on optimized probe-surface density and ionic strength control. The changes observed in the SPR signal were always larger for WT compared with the single-mismatch target DNA oligonucleotides, and were aligned with the theoretical energy differences between the base pair C-G, C-T, C-A, C-C. Hybridization rates of ∼106M-1s-1 were detected without the introduction of high temperature and labels, usually needed in conventional hybridization methods. One hundred percent mutation discrimination of the matched KRAS wild-type (C-G) sequence with respect to three mismatched G12C (C-T), G12 S (C-A), G12 R (C-C) target sequences was achieved.

An innovative chemical strategy for PCR-free genetic detection of pathogens by an integrated electrochemical biosensor.

An innovative chemical strategy integrated in a miniaturized electrochemical device was developed for sensitive detection of a pathogen genome (HBV virus) without any amplification step. The results show a limit of detection comparable to the standard qRT-PCR method (20 copies per reaction), paving the way to future development of genetic PoC devices addressing automatized and low-cost molecular diagnostics.

Electrochemical Switching of Chromogenic Monolayers Self-Assembled on Transparent Platinum Electrodes.

Transparent, ultrathin Pt electrodes permit the simultaneous electrochemical and spectroscopic investigation of self-assembled monolayers of electrochromic compounds. Voltage stimulations applied to the Pt substrate reversibly alter the redox state of the chemisorbed molecules and, hence, modulate the intensity of the light transmitted through the Pt/monolayer assembly.

Tetrametallic Reduction of Dinitrogen: Formation of a Tetranuclear Samarium Dinitrogen Complex.

The cooperative attack of four (dipyrromethanyl)Sm(II) units on dinitrogen resulted in a novel tetranuclear samarium dinitrogen complex (shown schematically). The presence of halogen atoms inhibited reactivity with dinitrogen through the assembly of divalent samarium clusters. dipyrr=diphenylmethyldipyrrolide dianion.