Related Experiment Video
Updated: Aug 17, 2026
A Method for Selecting Structure-switching Aptamers Applied to a Colorimetric Gold Nanoparticle Assay
Published on: February 28, 2015
A disposable aptasensor based on a gold-plated coplanar electrode array for on-site and real-time determination of
Haochen Qi1, Xiaofan Huang2, Jayne Wu3
1College of Electrical and Electronic Engineering, Wenzhou University, Wenzhou, 325035, China; School of Electronic Science and Applied Physics, Hefei University of Technology, Hefei, 230009, China.
Abstract:
Copper ion (Cu2+) is an important cofactor for many enzymes in human body. Either excessive or deficient Cu2+ in the body may cause serious dysfunctions and diseases. So sensitive determination of Cu2+ in environmental samples is of more significance for evaluation and control of Cu2+ intake. Based on a low-cost gold-plated coplanar electrode array, a disposable aptasensor is developed with an ultra-sensitive indicator of interfacial capacitance. Modified with a specially isolated DNA aptamer for Cu2+, this sensor achieves a high selectivity of 1207: 1 against non-target ions. To realize real-time response, alternating-current electrothermal effect is integrated into the capacitance measuring process to efficiently enrich the trace Cu2+. This sensor reaches a limit of detection of 2.97 fM, with a linear range from 5.0 fM to 50 pM. The response time is only 15 s, which can meet the real-time detection requirement. On-site test of practical samples is also realized using the disposable sensor combined with a handheld inductance/capacitance/resistance meter. This sensor with its portable test system provides a cost-efficient solution for on-site, real-time and sensitive detection of Cu2+, showing great application value in environment monitoring.
