A spectrophotometric method for the detection of tyrosinase activity is developed by utilizing the product-triggered aggregation of boronic acid-functionalized gold nanoparticles. Based on the changes of absorbance in UV-visible spectra, the assay shows extremely high sensitivity and lowered limit of detection of 1 × 10(-10) u mL(-1).

a solid phase extraction sorbent based on polyaniline/graphene nanocomposite is presented. the structure and morphology of synthesized nanocomposite were investigated by fourier transform infrared spectroscopy, field emission scanning electron microscopy, x-ray diffraction and thermal gravimetric analysis. the dispersive solid phase extraction was employed to the isolation and preconcentration ...

A highly selective and sensitive chemodosimeter for detection of cyanide ions in HEPES buffer and in the presence of blood serum using a ratiometric approach through dual UV-Vis and fluorescence channels with the lowest detection limit of 0.08 ppb has been synthesized.

Sheath-flow surface-enhanced Raman spectroscopy (SERS) was used for online detection and quantification of small molecules separated by liquid chromatography. A mixture of model metabolites (thiamine, folic acid, and riboflavin) was separated and characterized by UV-Vis and SERS detectors connected in series. Acetonitrile in the mobile phase provided an internal standard enabling quantitative d...

We demonstrate a proof-of-concept optical spectroscopic system for bioaerosol-particle fluorescence detection, in which a pulsed high-power laser is replaced by a highly compact linear array of sequentially fired light from blue light-emitting diodes. The results suggest that low-cost, compact optical aerosol detection may be feasible with the contemporary emergence of efficient UV light-emitti...

By combining terminal protection of small molecule (folate)-capped DNA probes, exonuclease III signal amplification and gold nanoparticles, we developed a simple and label-free colorimetric assay for highly sensitive detection of folate receptor (FR). A detection limit of 50 fM FR was obtained using UV-vis spectrometry and 10 pM FR could be visualized by the naked eye.

Scalable microfabrication technology has enabled semiconductor and microelectronics industries, among other fields. Meanwhile, rapid and sensitive bio-molecule detection is increasingly important for drug discovery and biomedical diagnostics. In this work, we designed and demonstrated that photonic crystal sensor chips have high sensitivity for protein detection and can be mass-produced with sc...

UV-C radiation is known to induce metabolic modifications in plants, particularly to secondary metabolite biosynthesis. To assess these modifications from a global and untargeted perspective, the effects of the UV-C radiation of the leaves of three different model plant species, Cissus antarctica Vent. (Vitaceae), Vitis vinifera L. (Vitaceae) and Cannabis sativa L. (Cannabaceae), were evaluated...

How human DNA repair proteins survey the genome for UV-induced photoproducts remains a poorly understood aspect of the initial damage recognition step in nucleotide excision repair (NER). To understand this process, we performed single-molecule experiments, which revealed that the human UV-damaged DNA-binding protein (UV-DDB) performs a 3D search mechanism and displays a remarkable heterogeneit...

PURPOSE Induction of oxidative stress has been implicated in UV-induced melanoma. We sought to determine whether the antioxidant N-acetylcysteine (NAC) could be safely administered to protect melanocytic nevi from the oxidative stress resulting from acute UV exposure. EXPERIMENTAL DESIGN Patients at increased risk for melanoma were recruited from a screening clinic. Induction and detection of...