Phosphate Assay Kit in One Cell for Electrochemical Detection of Intracellular Phosphate Ions at Single Cells

Abstract

In this paper, phosphate assay kit in one cell is realized for the electrochemical detection of intracellular phosphate ions at single cells. The components of the phosphate assay kit, including maltose phosphorylase, maltose, mutarotase, and glucose oxidase, are electrochemically injected into a living cell through a nanometer-sized capillary with the ring electrode at the tip. These components react with phosphate ions inside the cell to generate hydrogen peroxide that is electrochemically oxidized at the ring electrode for the qualification of intracellular phosphate ions. An average 1.7 nA charge was collected from eight individual cells, suggesting an intracellular phosphate concentration of 2.1 mM. The establishment in the electrochemical measurement of phosphate ions provides a special strategy to monitor the fluctuation of intracellular phosphate at single cells, which is significant for the future investigation of phosphate signal transduction pathway.

High phosphate actively induces cytotoxicity by rewiring pro‐survival and pro‐apoptotic signaling networks in HEK293 and HeLa cells

“…In mammalian cells, free intracellular phosphate concentration range is between 0.5 and 5 mM. 41,42 Bevington et al detected 0.4 and 4 mM intracellular phosphate in erythrocytes and myocytes respectively via 31 P nuclear magnetic resonance spectroscopy ( 31 P-NMR). 41 Electrochemical detection showed 2.1 mM free Pi in HeLa cells.…”

“…41 Electrochemical detection showed 2.1 mM free Pi in HeLa cells. 42 In this study, we intended to further explore the underlying molecular mechanisms of Pi cytotoxicity by adopting an acute cell stress model, in which cultured cells were exposed to higher than physiological levels of Pi (2.5 to 40 mM) and treated for a relatively shorter period (8 to 48 h). Cultured mammalian cells, depending on the cell type, respond differently to a wider range of extracellular phosphate in vitro.…”

“…Bevington et al detected 0.4 and 4 mM intracellular phosphate in erythrocytes and myocytes respectively via 31 P nuclear magnetic resonance spectroscopy ( 31 P‐NMR) 41 . Electrochemical detection showed 2.1 mM free Pi in HeLa cells 42 . In this study, we intended to further explore the underlying molecular mechanisms of Pi cytotoxicity by adopting an acute cell stress model, in which cultured cells were exposed to higher than physiological levels of Pi (2.5 to 40 mM) and treated for a relatively shorter period (8 to 48 h).…”

Fabrication and Characterization of Calcium-Phosphate Lipid System for Potential Dental Application

“…The calcium-phosphate lipid system has shown success in a wide range of treatment strategies due to its multiple properties, such as an efficient encapsulating ability and its antimicrobial properties (Verderosa et al, 2019), many of which were yet unexplored (Satterlee and Huang, 2016). Since 1970s, an attempt to characterize the calcium-phosphate complex to increase transfection efficiency and allow delivery has been made (Graham and van der Eb, 1973;Maitra, 2005;Sokolova et al, 2006;Xu et al, 2019). Lipids have broad application prospects since they were easily designed, synthesized, and characterized (Zhi et al, 2018;Williams and Grant, 2019).…”

Fluorescent Polymerase Chain Reaction Nanokit for the Detection of DNA Sequence in Single Living Cells

“…The peroxide is further detected by the ring electrode at the orifice of the nanopipette for the quantification of the target molecules. Many molecules, such as cholesterol, glucose, and sphingomyelinase, inside one living cell have been detected using this nanokit-based method. , Since this method used the well-developed kits, it can be easily adapted to the measurement of various molecules at single cells. The avoidance of the probe synthesis simplifies single cell measurement.…”