Continuous monitoring of bisulfide variation in microdialysis effluents by on-line droplet-based microfluidic fluorescent sensor.
We demonstrate a novel fluorescent sensor for real-time and continuous monitoring of the variation of bisulfide in microdialysis effluents by using a nanoparticle-glutathione-fluorescein isothiocyanate (AuNP-GSH-FITC) probe coupled with on-line droplet-based microfluidic chip. The AuNP-GSH-FITC fluorescent probe was firstly developed and used for bisulfide detection in bulk solution by quantitative real-time PCR, which achieved a linear working range from 0.1 μM to 5.0 μM and a limit of detection of ~50 nM. The response time was less than 2 min. With the aid of co-immobilized thiol-polyethylene glycol, the probe exhibited excellent stability and reproducibility in high salinity solutions, including artificial cerebrospinal fluids (aCSF). By adding 0.1% glyoxal to the probe solution, the assay allowed quantification of bisulfide in the presence of cysteine at the micro-molarity level. Using the AuNP-GSH-FITC probe, a droplet-based microfluidic fluorescent sensor was further constructed for online monitoring of bisulfide variation in the effluent of microdialysis. By using fluorescence microscope-charge-coupled device camera as the detector, the integrated microdialysis/microfluidic chip device achieved a detection limit of 2.0 μM and a linear response from 5.0 μM to 50 μM for bisulfide in the tested sample. The method was successfully applied for the on-line measurement of bisulfide variation in aCSF and serum samples. It will be a very useful tool for tracking the variation of bisulfide or hydrogen sulfide in extracellular fluids.
Beijing National Laboratory for Molecular Sciences, MOE Key Laboratory of Bioorganic Chemistry and Molecular Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
Xiaocui
X
Zhu
Beijing National Laboratory for Molecular Sciences, MOE Key Laboratory of Bioorganic Chemistry and Molecular Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
Lei
L
Xu
Beijing National Laboratory for Molecular Sciences, MOE Key Laboratory of Bioorganic Chemistry and Molecular Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
Tongbo
T
Wu
Beijing National Laboratory for Molecular Sciences, MOE Key Laboratory of Bioorganic Chemistry and Molecular Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
Anqin
A
Xu
Beijing National Laboratory for Molecular Sciences, MOE Key Laboratory of Bioorganic Chemistry and Molecular Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China. Electronic address: mpzhao@pku.edu.cn.
Meiping
M
Zhao
Department of Chemistry and Biochemistry, The University of Oklahoma, Norman, OK 73019, USA. Electronic address: shaorong.liu@ou.edu.
Shaorong
S
Liu
D015374:Biosensing Techniques / Q000295:instrumentation*; D002555:Cerebrospinal Fluid / Q000737:chemistry*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D017551:Microdialysis / Q000295:instrumentation*; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D008991:Monitoring, Physiologic / Q000295:instrumentation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000295:instrumentation*; D013440:Sulfides / Q000097:blood* / Q000134:cerebrospinal fluid*
D013440:Sulfides
Droplet-based microfluidics; Gold nanoparticle; Hydrogen sulfide; Microdialysis effluents; On-line detection