Simple and sensitive protein detection system using UV LEDs and liquid core waveguides

Abstract

Protein concentrations are traditionally analyzed in the ultraviolet at 280nm using laboratory spectrophotometers. Recently, AlGaN/GaN deep ultraviolet Light Emitting Diodes (LED) became available in the 250 nm to 350 nm wavelength region. An inexpensive fiber optic detection system based on these UV LEDs and photodiodes has been developed. Measurement stability, noise and drift will be discussed. To improve sensitivity of the detection system, microliter volume liquid core waveguide sampling cells with 10 cm and 50 cm pathlength were evaluated. With a continuous flow setup, protein concentrations as low as 1 µg/mL and 0.2 µg/mL were detectable in a 10 cm and a 50 cm pathlength cell respectively, based on a 10 mAU absorbance signal and a signal to noise ratio greater than 10.

Nitrogen-doped carbon dots/Fe3+-based fluorescent probe for the “off–on” sensing of As(v) in seafood

“…29 However, considering the rich protein in actual seafood, which had a maximum absorption peak at 280 nm, 260 nm was selected as the excitation wavelength for the subsequent studies. 30 Furthermore, the quantum yield of N–CDs in water was 7.14% for the emission at 522 nm, which performed better than ordinary CDs without nitrogen doping. 31,32…”

Influence of light-sources on UV fiber damage measured with DIN standard 58145

“…New, more sensitive and compact fiber optic spectroscopic applications and products were designed and established in a growing market 9,11,12 . UV fibers were used in high pressure liquid chromatography 13 , thin layer chromatography 14 , sensitive protein detection with UV LEDs and liquid core waveguides 15 , UV gas chromatography 16 , UV laser-based pollutant sensing 17 and colored dissolved organic matter (CDOM) detection in seawater 18 , only to name a few.…”