Real-time Cd2+ detection at sub-femtomolar level in various liquid media by an aptasensor integrated with microfluidic enrichment

SENSORS AND ACTUATORS B-CHEMICAL

卷:329

Article

Zhang, Jian^1,2  Zhang, Yuyu¹  Wu, Jayne³  Qi, Haochen¹  Zhao, Meiqi⁴  Yi, Maoxiang¹  Li, Zhenmin¹  Zheng, Lei² 

[1] Hefei Univ Technol, Sch Elect Sci & Appl Phys, Hefei 230009, Peoples R China

[2] Hefei Univ Technol, Sch Food & Biol Engn, Hefei 230009, Peoples R China

[3] Univ Tennessee, Dept Elect Engn & Comp Sci, Knoxville, TN 37996 USA

[4] Southeast Univ, Natl ASIC Syst Engn Res Ctr, Nanjing 210096, Peoples R China

关键词: Aptasensor;    Trace Cd2+ detection;    Capacitive sensing;    Microfluidic enrichment;   

DOI  :  10.1016/j.snb.2020.129282

来源: Elsevier

【 摘 要 】

Cadmium ion (Cd2+) is a highly toxic heavy metal pollutant with long biological half-life and strong bioaccumulation, which may cause irreversible damage to human health even at low-dose intake. Sensitive and specific detection of ultra-trace Cd2+ is of great significance in food safety and environmental monitoring. In this work, a simple-to-use aptasensor to rapidly detect Cd2+ in various liquid media is developed based on a DNA aptamer modified gold interdigitated electrode (IDE). Capacitance at the solid-liquid interface is utilized to reflect the change caused by adsorbed Cd2+. With the microfluidic enrichment by AC electrothermal (ACET) effect, Cd2+ ions are sped up toward the IDE surface and captured by the probes instantaneously. Owing to the integration of target enrichment and capacitance detection, the sample-to-result time of this sensor is as short as 30 s. This aptasensor as a quantitative detector has a linear response range from 0.45 fM to 4.5 pM, with a limit of detection of 253.16 aM. The selectivity ratio reaches 2320: 1 against non-target metal ions. By detection of Cd2+ spiked in tap water and olive oil as well as natural residual Cd2+ in rice leaching solution, the sensor's applicability and reliability in different practical liquid media are demonstrated.

【 授权许可】

Free