title: A cell-surface-anchored ratiometric fluorescent probe for extracellular pH sensing.
abstract: Accurate sensing of the extracellular pH is a very important yet challenging task in biological and clinical applications. This paper describes the development of an amphiphilic lipid-DNA molecule as a simple yet useful cell-surface-anchored ratiometric fluorescent probe for extracellular pH sensing. The lipid-DNA probe, which consists of a hydrophobic diacyllipid tail and a hydrophilic DNA strand, is modified with two fluorescent dyes; one is pH-sensitive as pH indicator and the other is pH-insensitive as an internal reference. The lipid-DNA probe showed sensitive and reversible response to pH change in the range of 6.0-8.0, which is suitable for most extracellular studies. In addition, based on simple hydrophobic interactions with the cell membrane, the lipid-DNA probe can be easily anchored on the cell surface with negligible cytotoxicity, excellent stability, and unique ratiometric readout, thus ensuring its accurate sensing of extracellular pH. Finally, this lipid-DNA-based ratiometric pH indicator was successfully used for extracellular pH sensing of cells in 3D culture environment, demonstrating the potential applications of the sensor in biological and medical studies.
authors.affiliation: State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, the Key Laboratory for Chemical Biology of Fujian Province, The MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Xiamen University , Xiamen 361005, P. R. China.
authors.forename: Guoliang
authors.initials: G
authors.lastname: Ke
authors.forename: Zhi
authors.initials: Z
authors.lastname: Zhu
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Yuan
authors.initials: Y
authors.lastname: Zou
authors.forename: Zhichao
authors.initials: Z
authors.lastname: Guan
authors.forename: Shasha
authors.initials: S
authors.lastname: Jia
authors.forename: Huimin
authors.initials: H
authors.lastname: Zhang
authors.forename: Xuemeng
authors.initials: X
authors.lastname: Wu
authors.forename: Chaoyong James
authors.initials: CJ
authors.lastname: Yang
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D002021:Buffers; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism*; D003094:Collagen / Q000494:pharmacology; D004247:DNA / Q000737:chemistry; D005110:Extracellular Space / Q000378:metabolism*; D005456:Fluorescent Dyes / Q000378:metabolism*; D005782:Gels; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008055:Lipids / Q000737:chemistry; D013050:Spectrometry, Fluorescence
chemical_list: D002021:Buffers; D005456:Fluorescent Dyes; D005782:Gels; D008055:Lipids; D003094:Collagen; D004247:DNA
keywords: cell surface anchorage; extracellular pH sensing; lipid−DNA; ratiometric fluorescent probe