title: A label-free microfluidic biosensor for activity detection of single microalgae cells based on chlorophyll fluorescence.
abstract: Detection of living microalgae cells is very important for ballast water treatment and analysis. Chlorophyll fluorescence is an indicator of photosynthetic activity and hence the living status of plant cells. In this paper, we developed a novel microfluidic biosensor system that can quickly and accurately detect the viability of single microalgae cells based on chlorophyll fluorescence. The system is composed of a laser diode as an excitation light source, a photodiode detector, a signal analysis circuit, and a microfluidic chip as a microalgae cell transportation platform. To demonstrate the utility of this system, six different living and dead algae samples (Karenia mikimotoi Hansen, Chlorella vulgaris, Nitzschia closterium, Platymonas subcordiformis, Pyramidomonas delicatula and Dunaliella salina) were tested. The developed biosensor can distinguish clearly between the living microalgae cells and the dead microalgae cells. The smallest microalgae cells that can be detected by using this biosensor are 3 μm ones. Even smaller microalgae cells could be detected by increasing the excitation light power. The developed microfluidic biosensor has great potential for in situ ballast water analysis.
authors.affiliation: College of Information and Science Technology, Dalian Maritime University, Dalian 116026, China. yqsun@dlmu.edu.cn.
authors.forename: Junsheng
authors.initials: J
authors.lastname: Wang
authors.forename: Jinyang
authors.initials: J
authors.lastname: Sun
authors.forename: Yongxin
authors.initials: Y
authors.lastname: Song
authors.forename: Yongyi
authors.initials: Y
authors.lastname: Xu
authors.forename: Xinxiang
authors.initials: X
authors.lastname: Pan
authors.forename: Yeqing
authors.initials: Y
authors.lastname: Sun
authors.forename: Dongqing
authors.initials: D
authors.lastname: Li
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods*; D002734:Chlorophyll / Q000737:chemistry*; D005453:Fluorescence; D058086:Microalgae / Q000737:chemistry*; D044085:Microfluidics / Q000295:instrumentation* / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000295:instrumentation / Q000379:methods
chemical_list: D014874:Water Pollutants, Chemical; D002734:Chlorophyll