Incoherent broadband cavity-enhanced absorption spectroscopy for sensitive measurement of nutrients and microalgae

Abstract

Incoherent broadband cavity-enhanced absorption spectroscopy (IBBCEAS) can achieve sensitive measurements at trace concentrations for liquid phase marine samples. The IBBCEAS system consists of a cavity-enhancement module (CEM) and a transmission hyperspectral module (THM). The CEM has cavity-enhancement factors up to 78 at 550 nm. Measurements were obtained over a wide wavelength range (420–640 nm) with a halogen lamp, and the optical cavity was formed by two concave highly reflective mirrors ( R = 0.99 ). The minimum detectable absorption coefficient α min of 7.3 × 1 0 − 7 c m − 1 at 550 nm corresponds to a limit of detection for nutrients of 780 pM. The spectral resolution of the THM is 3 nm in the wavelength range of 400 to 750 nm. We performed the IBBCEAS measurements for biological and chemical substances, including nutrients, microalgae, and Cy5 dye. The concentrations of nutrients in a deionized water environment and artificial seawater environment were measured at nanomolar levels; the concentration of microalgae phaeocystis was detected with 3.46 × 1 0 4 / m L , and fluorescence substances such as Cy5 dye could be measured at 0.03 mg/L. Experimental results show that the IBBCEAS system has the capability for sensitive measurements of biological and chemical substances and has strong potential for in situ ecological marine environmental monitoring function.

Investigate Spectroscopic Experimental and Theoretical Model for Hemoglobin Nanoscale Solution

“…To address these shortcomings, spectroscopic absorption techniques such as the CRDS, CEAS, and BBCEAS, which use an optical cavity to improve light interaction with matter inside a cavity, can be used to address very low concentrations of 10 nL; the method is less expensive 11,12 . Because most analytes are in the liquid phase [13][14][15][16] , it has a wide spectral range of wavelengths (190 nm to 10 m), high spatial resolution, and reliability, and it is considered very important in many medical fields, such as health monitoring.…”