Atcherley CW, Laude ND, Parent KL, Heien ML. Fast-scan controlled-adsorption voltammetry for the quantification of absolute concentrations and adsorption dynamics.
LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013;
29:14885-92. [PMID:
24245864 DOI:
10.1021/la402686s]
[Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Fast-scan cyclic voltammetry has depended on background subtraction to quantify small changes in neurotransmitter concentration. Because of this requirement, measurements of absolute concentrations using fast-scan cyclic voltammetry have been limited. Here we develop and characterize fast-scan controlled-adsorption voltammetry (FSCAV), which enables direct measurements of absolute concentrations in vitro without the use of flow injection to change the concentration. This enables probing the diffusion-controlled adsorption dynamics of biogenic amines and other adsorbing species. An implicit finite-difference model of mass-transport-limited adsorption was developed and is in agreement with experimental results. Optimization of FSCAV yielded a sensitivity of 81 ± 11 nA/μM for dopamine, corresponding to a limit of detection of 3.7 ± 0.5 nM. Through the combination of novel instrumentation and validated computer simulations, we show that FSCAV is an important measurement tool that can be used to determine absolute concentrations and study mass-transport-limited adsorption.
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