Nanoparticle-based assay for detection of S100P mRNA using surface-enhanced Raman spectroscopy.

The focus of this work is toward the development of a point-of-care (POC) handheld technology for the noninvasive early detection of salivary biomarkers. The initial of focus was the detection and quantification of S100 calcium-binding protein P (S100P) mRNA found in whole saliva for use as a potential biomarker for oral cancer. Specifically, a surface-enhanced Raman spectroscopy (SERS)-based approach and assay were designed, developed, and tested for sensitive and rapid detection of S100P mRNA.

Why does enzyme not leach from metal-organic frameworks (MOFs)? Unveiling the interactions between an enzyme molecule and a MOF.

The strong interactions between microperoxidase (MP-11) and Tb-mesoMOF were identified via Raman spectroscopic studies, which revealed that MP-11 molecules interact with the framework of Tb-mesoMOF through π···π interactions between the heme of MP-11 and the conjugated triazine and benzene rings in the organic ligand of Tb-mesoMOF. The strong interactions facilitate the retention of MP-11 molecules within the metal-organic framework (MOF) pores, which is in striking contrast with the severe leaching of MP-11 from MCM-41 due to the lack of specific interactions between enzyme molecules and the mesoporous silica material.

Effects of cations and anions as aggregating agents on SERS detection of cotinine (COT) and trans-3'-hydroxycotinine (3HC).

The sensitivity of surface-enhanced Raman spectroscopy (SERS) highly depends on experimental factors including aggregating agents and pH. Using silver nanoparticles as the substrate, the effect of five cationic (K(+), Na(+), Mg(2+), Li(+), Ca(2+)) and three anionic (Cl(-), Br(-), I(-)) aggregating agents was examined on the SERS detection of tobacco-related biomarkers, namely cotinine (COT) and trans-3'-hydroxycotinine (3HC). The optimal concentrations of the aggregating agents with respect to highest SERS intensity varied widely (from 1.

Detection of tobacco-related biomarkers in urine samples by surface-enhanced Raman spectroscopy coupled with thin-layer chromatography.

The nicotine metabolites, cotinine and trans-3'-hydroxycotinine (3HC) are considered as superior biomarkers for identifying tobacco exposure. More importantly, the ratio of 3HC to cotinine is a good indicator to phenotype individuals for cytochrome P450 2A6 activity and to individualize pharmacotherapy for tobacco addiction. In this paper, a simple, robust and novel method based on surface-enhanced Raman spectroscopy coupled with thin-layer chromatography (TLC) was developed to directly quantify the biomarkers in human urine samples.