School of Food Science and Engineering, Foshan University, Foshan 528000, China; Institute of Environment and Food Safety, Wuhan Academy of Agricultural Science, Wuhan 430065, China.
School of Food Science and Engineering, Foshan University, Foshan 528000, China.
Talanta. 2019 Jun 1;198:412-416. doi: 10.1016/j.talanta.2019.02.045. Epub 2019 Feb 10.
As an ubiquitous heavy metal pollutant, cadmium ion (Cd) 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 Cd. The specific recognition between the aptamer and Cd 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 Cd 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 Cd 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 Cd.
作为一种普遍存在的重金属污染物，即使在低浓度下，镉离子（Cd）也会对食品和人体健康造成危害。传统方法需要昂贵的仪器，无法满足现场分析的要求。在这里，我们报告了使用个人血糖仪（PGM）作为现场即时（POU）设备，用于便携式和定量检测 Cd。适体与 Cd 之间的特异性识别触发了外切酶 III（Exo III）的循环信号放大过程。经过连续的杂交和切割反应，大量的单链 DNA 被释放到磁珠表面。引入与单链 DNA 互补的连接有蔗糖酶的 DNA 进入传感系统。磁分离后，蔗糖酶将蔗糖水解成葡萄糖，从而将 Cd 浓度直接转化为葡萄糖量，这可以通过 PGM 直接定量。得益于 Exo III 和蔗糖酶的协同信号放大，POU 设备大大提高了 Cd 分析的灵敏度，检测限为 5pM。由于具有便携性、成本效益、广泛可用性和易用性等优点，基于 PGM 的检测器有可能被公众用作可靠和定量检测 Cd 的常规工具。
