Protein aggregation is phenomenon wherein protein loses its native structure and aggregates due to the adaption of non-native conformation. Amyloid aggregation formed by the accumulation of various proteins causes many diseases in humans and other organisms. Antioxidants can prevent proteins aggregation. Pulicaria undulata  extract along with phenolic compounds can increase protein stability an...

Novel optical techniques for sensitive and reproducible fluorescence single cell analysis utilizing setups without single photon counting units are attractive for enhanced low-cost cell parameter screening. In this contribution we present the first microfluidic planar device to form an optofluidic adjustable convex lens with three-dimensional light focusing ability to improve optical sensor sys...

A simple and sensitive methodology for the simultaneous determination of levodopa and carbidopa in pharmaceutical samples is described. The method combines the advantages of fluorescence with partial least-squares (PLS) analysis, and requires no previous separation steps. The developed method is based on the oxidation of levodopa and carbidopa by cerium(IV) in a sulfuric acid medium and monitor...

This paper presents a new research study on the platform fabrication of fluorescence bio-detection chip with an optical fiber transmission. Anisotropic wet etching on (100) silicon wafers to fabrication V-groove for optical fiber alignment and micro-mirror were included. Combing with anodic bonding technique to adhere glass, silicon structure and optical fiber for a fluorescence excitation plat...

The mangrove habitat exhibits many unique physical features, one of the most important of which is a salinity gradient. Photosynthetic rates, as measured by leaf stomatal conductance and leaf chlorophyll fluorescence induction, were tested as indicators of salinity stress in seedlings of the red mangrove, Rhizophora mangle, grown under five different salinity levels: 0, 15, 30, 45, and 60 parts...

This study was conducted to determine effect of water stress on chlorophyll content and chlorophyll fluorescence parameter in young `Dezful’ olive trees. Three irrigation regimes (40% ETcrop, 65% ETcrop and 100% ETcrop) were used. After irrigation treatments were applied, some of biochemical parameters including chlorophyll a, b, total chlorophyll, chlorophyll fluorescence and also chlorophyll ...

This study investigates the effect of photobleaching on laser-induced fluorescence (LIF) measurements. Photobleaching causes the fluorescence to be velocity-dependent, which is undesirable if quantitative measurements are being made. To quantify this effect, simultaneous and coincident measurements of fluorescence and velocity were made within the measuring volume of a three-beam laser-Doppler ...

In this paper, an application of negative curvature hollow core fiber (NCHCF) in an all-fiber, multiphoton fluorescence sensor setup is presented. The dispersion parameter (D) of this fiber does not exceed the value of 5 ps/nm × km across the optical spectrum of (680-750) nm, making it well suited for the purpose of multiphoton excitation of biological fluorophores. Employing 1.5 m of this fibe...

Intracellular viscosity is a crucial parameter that indicates the functioning of cells. In this work, we demonstrate the utility of TPE-Cy, a cell-permeable dye with aggregation-induced emission (AIE) property, in mapping the viscosity inside live cells. Owing to the AIE characteristics, both the fluorescence intensity and lifetime of this dye are increased along with an increase in viscosity. ...

Intracellular viscosity is a fundamental physical parameter that indicates the functioning of cells. In this work, we developed a simple boron-dipyrromethene (BODIPY)-based probe, BTV, for cellular mitochondria viscosity imaging by coupling a simple BODIPY rotor with a mitochondria-targeting unit. The BTV exhibited a significant fluorescence intensity enhancement of more than 100-fold as the so...