Measurement of Biomimetic Deposition of Calcium Phosphate in Real Time Using Complex Capacitance

Abstract

Deposition of minerals, particularly calcium phosphates such as hydroxyapatite, is an important process in the formation of hard tissues such as bone. Herein, a new, affordable, straightforward and nondestructive method based on complex capacitance spectroscopy, an application of electrochemical impedance spectroscopy, is described which allows repeated and real‐time measurements of the same sample throughout the calcium phosphate deposition process. In contrast with end‐point assays which require large numbers of samples to obtain useful time‐course data, this method allows the kinetics of deposition to be measured using a single sample by measuring the impedance of a pair of interdigitated electrodes at a range of frequencies as the layer of mineral is deposited. Changes in the complex capacitance curve over time with deposition can be compared with images of the coating deposited on model substrates, and show different behavior depending on the composition of the coating and the conditions of deposition.

Optimization of a tunable process for rapid production of calcium phosphate microparticles using a droplet-based microfluidic platform

“…On the other hand, a closer-to-amorphous apatitic phase in the case of CaSrZnP1.67-BS was detected. The SEM characterization ( Figure 9B ) showed that the new CaPs formed on the surface of microparticles has morphologies previously observed in (biomimetic) CaPs formed in simulated body fluids ( Barradas et al, 2013 ; Guttenplan et al, 2021b ). No specific trends in the surface roughness levels could be observed ( Supplementary Figure S5 ).…”

Redoxless Electrochemical Capacitance Spectroscopy for Investigating Surfactant Adsorption on Screen-Printed Carbon Electrodes

“…Though redoxless EIS has been common in corrosion research, it has received less attention from biosensor researchers. A few researchers have attempted to apply redoxless EIS or ECS to the investigation of the dielectric properties of self-assembled monolayers (SAMs) [28], biomimetic deposition of calcium phosphate [29], and direct detection of lead ions in tap water [30]. Recently, redoxless impedimetric methods have been applied to biochemical analysis, including the detection of ions [31], D-dimers [32], and low-molecular-weight triamterene [33].…”