Broadband cavity-enhanced absorption spectroscopy has been used to record, in real time, the absorption spectrum of microlitre volume aqueous phase droplets within a microfluidic chip assembly. Using supercontinuum radiation and broadband coated external mirrors, the full visible spectrum (430 nm < λ < 700 nm) of each passing droplet is acquired in situ at high repetition rates (273 Hz/3.66 ms acquisition time) and high sensitivity (α(min) < 10(-2) cm(-1)). The possibilities for further improvements in sensitivity and acquisition rate using custom designed chips are discussed.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1039/c1lc20854c | DOI Listing |
Talanta
December 2024
School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai, 200093, China. Electronic address:
Nitrous acid (HONO) is crucial in atmospheric chemistry as it is a major precursor for hydroxyl radicals (OH), the dominant atmospheric oxidant. Hydroxyl radicals are essential in the formation of secondary air pollutants like ozone and particulate matter. This study presents a newly developed Incoherent Broadband Cavity Enhanced Absorption Spectroscopy (IBBCEAS) system for precise and rapid measurements of HONO and nitrogen dioxide (NO) emissions.
View Article and Find Full Text PDFACS Sens
December 2024
State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, P. R. China.
Sulfur dioxide (SO) and nitrogen dioxide (NO) are chemical indicators of crop straw combustion as well as significant atmospheric pollutants. It is challenging to promptly detect natural "wildfires" during agricultural production, which often lead to uncontrollable and substantial economic losses. Moreover, both "wildfires" and artificial "straw burning" practices pose severe threats to the ecological environment and human health.
View Article and Find Full Text PDFFood Chem
February 2025
School of Health and Life Sciences, Teesside University, Middlesbrough, UK.
This study investigates the integration of Broadband Cavity Enhanced Absorption Spectroscopy (BBCEAS) with High-Performance Liquid Chromatography (HPLC) to detect synthetic antioxidants; BHA, BHT, and TBHQ in the deep-UV region below 300 nm. The research addresses the need for more sensitive and cost-effective detection methods in HPLC systems, particularly for low analyte concentrations, by exploring BBCEAS as a superior alternative to conventional detectors that often fall short in sensitivity. The sensitivity of the HPLC-BBCEAS system is assessed by calculating the minimum detectable change in the absorption coefficient (αmin) and comparing with those obtained using conventional HPLC and single-wavelength HPLC-CRDS methods.
View Article and Find Full Text PDFAdv Mater
August 2024
Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstrasse 36, 10623, Berlin, Germany.
We report on multi-resonance chirped distributed Bragg reflector (DBR) microcavities. These systems are employed to investigate the light-mater interaction with both intra- and inter-layer excitons of transition metal dichalcogenide (TMDC) bilayer heterostructures. The chirped DBRs consisting of SiO and SiN layers of gradually varying thickness exhibit a broad stopband with a width exceeding 600 nm.
View Article and Find Full Text PDFAn extremely conspicuous passive power noise stabilization is the first, to the best of our knowledge, discovered in a cavity-enhanced second-harmonic generation (SHG) process. Differing from the SHG as a buffer reservoir, the stronger strength of the nonlinear interaction pushes the power noise suppression level to a higher value and exhibits a broadband noise reduction performance due to the mechanism of dynamic pump suppression in the SHG process. The noise is suppressed to near shot noise limit (SNL) among the kHz to MHz frequency range, accompanied by a maximum noise reduction of 35 dB.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!