Living algae detection with a PDMS-liquid chlorophyll fluorescence microfluidic chip filter and a smartphone. Issue 16 (13th July 2022)

• Record Type: Journal Article
• Authors: Liu, Jianhua; Chang, Hui; Zhang, Xiangyu; Chen, Shimeng; Song, Yongxin; Li, Dongqing
• Is Part Of: Analyst. Volume 147:Issue 16(2022)
• Page Start: 3723
• Page End: 3731
• Publication Date: 2022-07-13
• Subjects: Chemistry, Analytic -- Periodicals; 543
• DOI: 10.1039/d2an00375a
• Languages: English
• ISSNs: 0003-2654

Abstract

Abstract : A PDMS-liquid chlorophyll fluorescence microfluidic chip filter for living algae detection. The filter has a top layer of crystal violet solution and a Sudan II-doped PDMS microchannel. Living algae detection with this microfluidic chip and a smartphone was achieved. Abstract : Building an optical filtration function into a microfluidic chip is a promising way of simplifying the optical detection system of a microfluidic device. In this paper, a PDMS microfluidic chip filter that is capable of transmitting chlorophyll fluorescence and blocking interfering light in the visible wavelength range was developed for living algae detection with a smartphone. The chip was fabricated by sealing a layer of crystal violet solution in a PDMS layer on the top of the Sudan II-doped PDMS slab, which has a straight microchannel. Optimum dye concentrations and thicknesses for the crystal violet solution layer and Sudan II-doped PDMS slab were investigated and determined by spectrum measurements. It was found that the cut-on range of this integrated microfluidic chip is extended to about 625 nm and the transmittance in the chlorophyll fluorescence range (650 nm to 710 nm) is as high as 95%, when 25 mg L −1 Sudan II-doped PDMS slab (with a 3 mm thickness) and 2 mg L −1 crystal violet solution (with a 0.3 mm thickness) were used. Living algae detection using this chlorophyll-fluorescence-filtering PDMS microfluidic chip and a smartphone-based imaging platform was achieved, and the results compared favorably with those using a commercial filter.