As an ubiquitous heavy metal pollutant, cadmium ion (Cd2+) is detrimental to food and human health even at low concentrations. Conventional methods require costly instruments and cannot meet the requirements of on site analysis. Here we report the use of a personal glucose meter (PGM) as the point-of-use (POU) device for portable and quantitative detection of Cd2+. The specific recognition between the aptamer and Cd2+ trigger the recycling signal amplification process by exonuclease III (Exo III). After successive hybridization and cleavage reactions, numerous single-stranded DNA were liberated on the surface of the magnetic bead. An invertase-conjugated DNA that is complementary to the single-stranded DNA is introduced into the sensing system. After magnetic separation, the invertase conjugates hydrolyze sucrose into glucose, thus establishing direct conversion of Cd2+ concentration to glucose amount, which can be directly quantified by a PGM. Thanks to the synergistic signal amplification of Exo III and invertase, the POU device greatly improves the sensitivity for Cd2+ analysis, with a detection limit of 5 p.M. With the advantages of portability, cost-effectiveness, wide availability, and ease of use, the PGM-based detector has the potential to be used by the public as a routine tool for reliable and quantitative detection of Cd2+. Publication name | TALANTA, 198 412-416; 10.1016/j.talanta.2019.02.045 JUN 1 2019 | Author(s) | Zeng, Lingwen; Gong, Junyu; Rong, Peisen; Liu, Chengshuai; Chen, Junhua | Corresponding author(s) | CHEN Junhua 222chenjunhua@163.com Guangdong Inst Ecoenvironm Sci & Technol, Guangdong Key Lab Integrated Agroenvironm Pollut, Guangzhou 510650, Guangdong, Peoples R China. | Author(s) from IGCAS | LIU Chengshuai | View here for the details
|
|
|