Kim Sangsik, Romero-Lozano Anakaren, Hwang Dong Soo, Yoon Jeong-Yeol
Department of Biosystems Engineering, The University of Arizona, Tucson, AZ 85721, United States; Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongsangbuk-do 37673, Republic of Korea.
Department of Biomedical Engineering, The University of Arizona, Tucson, AZ 85721, United States.
J Hazard Mater. 2021 Jul 5;413:125338. doi: 10.1016/j.jhazmat.2021.125338. Epub 2021 Feb 5.
Protamine, a guanidinium rich polymer, is proposed as a universal bioreceptor for bacteria, towards rapid and handheld bacteria detection from complex environmental water samples without the need for specific antibodies or primers. Escherichia coli K12, Salmonella Typhimurium, and Staphylococcus aureus (MSSA) were assayed, representing gram-negative, gram-positive, rod- and round-shaped bacteria. Samples and the protamine conjugated fluorescent particles were sequentially loaded to the paper microfluidic chips and flowed through the channels spontaneously via capillary action. The particles were aggregated via protamine-bacteria membrane interactions and unbound particles were rinsed via capillary action. A low-cost smartphone fluorescence microscope was designed, fabricated, and imaged the paper channels. A unique image processing algorithm isolated only the aggregated particles to detect all three bacteria (p < 0.05) with a detection limit of 10-10 CFU/mL. Protamine did not induce any particle aggregation with a model protein, algae, and virus. Successful bacteria detection was also demonstrated with environmental field water samples. Total assay time was < 10 min with neither extraction nor enrichment steps. In summary, a guanidinium-rich polymer showed a promise as a universal bioreceptor for bacteria and can be used on a paper microfluidic chip and smartphone quantification towards rapid and handheld detection.
鱼精蛋白是一种富含胍基的聚合物，被提议作为一种通用的细菌生物受体，用于从复杂的环境水样中快速、手持式检测细菌，无需特定抗体或引物。对大肠杆菌K12、鼠伤寒沙门氏菌和金黄色葡萄球菌（甲氧西林敏感金黄色葡萄球菌）进行了检测，分别代表革兰氏阴性菌、革兰氏阳性菌、杆状菌和圆形菌。将样品和与鱼精蛋白偶联的荧光颗粒依次加载到纸质微流控芯片上，并通过毛细作用自发地流过通道。颗粒通过鱼精蛋白与细菌膜的相互作用而聚集，未结合的颗粒通过毛细作用被冲洗掉。设计、制作了一种低成本的智能手机荧光显微镜，并对纸质通道进行成像。一种独特的图像处理算法仅分离聚集的颗粒，以检测所有三种细菌（p<0.05），检测限为10-10 CFU/mL。鱼精蛋白与模型蛋白、藻类和病毒不会诱导任何颗粒聚集。利用环境水样也证明了细菌检测的成功。总检测时间<10分钟，无需提取或富集步骤。总之，一种富含胍基的聚合物有望作为一种通用的细菌生物受体，可用于纸质微流控芯片和智能手机定量分析，实现快速、手持式检测。
