Korea Food Research Institution, Consumer Food Safety Research Department, Wanju-gun, Jeonrabuk-do 55365, South Korea.
Korea Food Research Institution, Consumer Food Safety Research Department, Wanju-gun, Jeonrabuk-do 55365, South Korea; Chonbuk National University, Department of Food Science and Technology, Jeonju-si, Jeollabuk-do 54896, South Korea.
Food Chem. 2019 Dec 1;300:125177. doi: 10.1016/j.foodchem.2019.125177. Epub 2019 Jul 13.
A point-of-care testing chip was developed for the colorimetric detection of inorganic mercury ion (Hg). The disposable chip fabricated by three-dimensional printing technology contains DNAzymes produced by rolling circle amplification (RCA); a color change caused by the enzymatic reaction between DNAzymes and the peroxidase substrate 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) is measured using a portable spectrophotometer. In the "turn-off"-type RCA reaction, the annealing of the T(12) primer that initiates the RCA reaction is blocked by the interaction of thymine with Hg; thus, the amount of amplified DNAzymes causing a color change is decreased depending on Hg concentration. The colorimetric signal is enhanced by amplifying double-repeat DNAzymes from a circular DNA template. The chip detected Hg in tap drinking water samples with high sensitivity (lowest validated value: 3.6 μg/L) and showed better selectivity, precision, and reproducibility than conventional analysis instruments. This low-cost easy-to-use platform can reduce the risk of accidental Hg poisoning.
一种用于比色检测无机汞离子（Hg）的即时检测芯片被开发出来。该一次性芯片采用三维打印技术制造，其中包含通过滚环扩增（RCA）产生的 DNA 酶；使用便携式分光光度计测量 DNA 酶与过氧化物酶底物 2,2'-联氮双（3-乙基苯并噻唑啉-6-磺酸）之间的酶促反应引起的颜色变化。在“关闭”型 RCA 反应中，T（12）引发 RCA 反应的引物的退火被胸腺嘧啶与 Hg 的相互作用阻断；因此，根据 Hg 浓度，导致颜色变化的扩增 DNA 酶的量减少。通过从圆形 DNA 模板扩增双重复 DNA 酶来增强比色信号。该芯片以高灵敏度（经验证的最低值：3.6μg/L）检测自来水中的 Hg，并且比传统分析仪器具有更好的选择性、精密度和重现性。这种低成本、易于使用的平台可以降低意外 Hg 中毒的风险。
