Terminal-conjugated non-aggregated constraints of gold nanoparticles on lateral flow strips for mobile phone readouts of enrofloxacin

• Published in: Biosensors & bioelectronics Vol. 160; p. 112218
• Main Authors: Tian, Run, Ji, Jinyu, Zhou, Yangyang, Du, Yumei, Bian, Xiaojun, Zhu, Fulin, Liu, Gang, Deng, Shengyuan, Wan, Ying, Yan, Juan
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 15.07.2020
• Subjects: absorption; Animals; Anti-Bacterial Agents - analysis; antibiotics; Aptamer; Aptamers, Nucleotide - chemistry; aptasensors; AuNP proximity; Biosensing Techniques - instrumentation; Biosensing Techniques - methods; cameras; Cell Phone; color; Enrofloxacin; Enrofloxacin - analysis; Equipment Design; Food Contamination - analysis; Gold - chemistry; Honey - analysis; information processing; Lateral flow biosensor; Limit of Detection; metabolites; Metal Nanoparticles - chemistry; Milk - chemistry; mobile telephones; Models, Molecular; moieties; monitoring; nanogold; nucleotidyltransferases; point-of-care systems; public health; Reagent Strips - analysis; Terminal deoxynucleotidyl transferase; topography; Lateral flow biosensor; Aptamer; Terminal deoxynucleotidyl transferase; AuNP proximity; Enrofloxacin
• ISSN: 0956-5663; 1873-4235; 1873-4235
• DOI: 10.1016/j.bios.2020.112218

Antibiotics abuse now poses a global threat to public health. Monitoring their residual levels as well as metabolites are of great importance, still challenges remain in in situ tracing during the circulation. Herein, taking the typical antibacterial Enrofloxacin (ENR) as a subject, a paper-based aptasensor was tailored by manipulating a duo of aptameric moieties to “sandwich” the target in a lateral-flow regime. To visualize the tight-binding sandwich motif more vividly, an irregular yet robust DNA-bridged gold nanoparticles (AuNPs) proximity strategy was developed with recourse to terminal deoxynucleotidyl transferase, of which the nonaggregate constraining feature was unveiled via optical absorption and scanning probe topography. This complex performed exceptionally better in the test strip context than single-particle tags, leading to an enhanced on-chip focusing. Rather than qualitative color developing, further efforts were taken to visualize the readouts in a quantitative manner by exploiting the smartphone camera for pattern recognition along with data processing in a professional App. Overall, this prototyped contraption realized a rapid and ultrasensitive quantification of ENR down to 0.1 μg/L along with a broad linear range over 5 orders of magnitude, plus excellent selectivity and precision even for real samples. Such innovative fusion across DNA-structured nanomanufacturing and intelligent perception provides a prospective and invigorating solution to point-of-care inspection. •A lateral-flow strip was fabricated as a miniaturized contraption for point-of-care test of Enrofloxacin the antibiotics.•A duo of aptamer moieties was manipulated in the paper-based setup that realized a specific target binding during wicking.•Template-free polymerase-assisted gold nanoparticles proximity was recruited as a robust and over-qualified color developer.