Stochastic Electrochemical Cytometry of Human Platelets via a Particle Collision Approach

Abstract

The quantitative analysis of human platelets is important for the diagnosis of various hematologic and cardiovascular diseases. In this article, we present a stochastic particle impact electrochemical (SPIE) approach for human platelets with fixation (F-HPs). Carboxylatefunctionalized polystyrene particles (PSPs) are studied as well as a standard platform of SPIE-F-HPs. For SPIE-PSPs (or F-HPs), [Fe-(CN) 6 ] 4− was used as the redox mediator, and electro-oxidation of [Fe(CN) 6 ] 4− to [Fe(CN) 6 ] 3− was conducted on a Pt ultramicroelectrode (UME) by applying a constant potential, where the corresponding oxidation current is mass-transfer-controlled. When PSPs (or F-HPs) are introduced into aqueous solution with [Fe(CN) 6 ] 4− , sudden current drops (SCDs) were observed, which resulted from the partial blockage of a Pt UME by collision of an individual PSP (or F-HP). For SPIE-PSPs (or F-HPs), we found that it is essential to enhance the migration of PSPs (F-HPs) toward a Pt UME by maximizing the steady state current associated with electro-oxidation of [Fe(CN) 6 ] 4− . This was accomplished by increasing its concentration to the solubility limit. We successfully measured the concentration of F-HPs dispersed in aqueous solution containing [Fe(CN) 6 ] 4− with a minimum detectable concentration of 0.1 fM, and the size distribution of F-HPs was also estimated from the obtained i drop distribution based on the SPIE analysis, where i drop stands for the magnitude of the current drop of each SCD. Lastly, we revealed that HPs without the fixation process (WF-HPs) are difficult to quantitatively analyze by SPIE because of their transient activation process, which results in changes from their spherical shape. The observed difficulty was also confirmed by finite element analysis, which shows that i drop can be significantly increased, as an elongated WF-HP is adsorbed on the edge of an UME.

Rapid and Accurate Data Processing for Silver Nanoparticle Oxidation in Nano-Impact Electrochemistry

“…The collision entities are further extended to biospecies, such as enzymes ( Lin et al, 2017 ; Wang et al, 2021 ), cells ( Dick, 2016 ; Gooding, 2016 ; Lee et al, 2020 ), bacterium ( Lee et al, 2016 ; Gao et al, 2018 ; Chen et al, 2021 ), and viruses ( Sepunaru et al, 2016 ). During the impact of the single entities to the electrode, electrochemical reactions will take place, including the direct electrolysis of the entities themselves ( Zhou et al, 2012a ; Zhou et al, 2012b ), the electrocatalytic reactions occurring on the surfaces of the entities ( Patrice et al, 2018 ; Xiang et al, 2018 ; Du et al, 2020 ),and diffusion blocking of the electroactive species by electrochemically inert entities ( Dick et al, 2015 ; Lee et al, 2019 ).…”

Single Microcystis Detection Through Electrochemical Collision Events on Ultramicroelectrodes

“…Collision signal analysis of individual particles using electrochemistry began with hard particles such as those of Ag, 1,2 Au, 3 Pt 4 and was extended to soft particles such as emulsion particles, [5][6][7][8][9][10][11] polymers, 12 vesicles, [13][14][15][16] viruses, [17][18][19] bacteria, 20,21 cells, [22][23][24][25] enzymes, 26 and proteins. 27 The scope of this field of study is gradually expanding.…”

“…Our group has conducted single-entity collision studies on various soft particles. 8,10,22,24,28 In this article, we report the collision of microcystis (MCS) on an electrode. MCS disturbs the ecosystem balance with its mass growth and causes water pollution by generating toxins.…”

“…Our group has conducted single‐entity collision studies on various soft particles 8,10,22,24,28 . In this article, we report the collision of microcystis (MCS) on an electrode.…”

Stochastic Particle Approach Electrochemistry (SPAE): Estimating Size, Drift Velocity, and Electric Force of Insulating Particles

“…The electrochemical analyses of submicron particles and nanoparticles by their stochastic collisions on an electrode, i.e., stochastic particle impact electrochemistry (SPIE), has been proven as a powerful approach to study the physicochemical characteristics of single entities. To date, SPIE has been used to study metals, − semiconductors, carbon particles, , clays, insulators, − droplets, − emulsions, − micelles, − vesicles, , and enzymes. , For SPIE analyses, the origins of stochastic sudden current spikes or staircase current increases (or decreases) induced by individual particles strongly depend on the type of analyzed particles. There are four types of SPIE analyses that have been reported. , In the first type (Type-I SPIE ), the particles for SPIE analysis are redox-active and can be directly electroreduced (or oxidized) during individual collisions on an electrode.…”