Rapid and sensitive detection of formaldehyde based on AC electrokinetic effects

Formaldehyde is a toxic water-soluble organic matter. Its detection methods and detection limit have been attracting more attentions. An AC electrokinetic (ACEK)-enhanced capacitive sensing method for rapid detection of trace formaldehyde in liquid is presented using commercial microelectrode chips. By this method, a detection limit is achieved as low as 0.01 ppm (g/ml) within a 60 s response time. It is proved that the trace amount of formaldehyde in common solvents can also be effectively detected. As a complement, the capacitance change rate dependence on testing voltage and frequency is investigated. Compared to other existing detection methods, this ACEK-based capacitive method is a low cost, high sensitive and fast detection means, which shows a great application prospect in industry and research such as food safety and specimen cleaning.