Printed Graphene Electrochemical Biosensors Fabricated by Inkjet Maskless Lithography for Rapid and Sensitive Detection of Organophosphates
Printed Graphene Electrochemical Biosensors Fabricated by Inkjet Maskless Lithography for Rapid and Sensitive Detection of Organophosphates
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DOI：
10.1021/acsami.7b19763
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发表时间：
2018-04-04
影响因子：
9.5
通讯作者：
Caussen, Jonathan C.
中科院分区：
文献类型：
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作者：
Hondred, John A.;Breger, Joyce C.;Caussen, Jonathan C.
石墨烯电极的液相印刷最近成为一种有吸引力的低成本、可扩展的制造技术，用于制造现场电化学生物传感器。在这里，我们报告了通过喷墨无掩模光刻（IML）开发的石墨烯基电极，用于直接和快速监测三o连接的膦酸有机磷酸盐（OPs）；这些构成了化学战剂和杀虫剂中发现的活性化合物，它们表现出急性毒性以及对土壤和水道的长期污染。iml印刷的石墨烯电极是纳米/微结构的，采用1000 mW台式激光雕刻机和电化学沉积的铂纳米颗粒（直径为10nm）。以提高其导电性（薄片电阻从10,000 ω /sq降低到100 ω /sq）、表面积和电活性，从而实现后续的酶功能化和生物传感。磷酸三酯酶（PTE）通过戊二醛交联偶联到电极表面。所制备的生物传感器能够快速测量杀虫剂对氧磷（一种模型OP），响应时间为5 s，检测限低（3 nM），灵敏度高（370 nA/mu M），可忽略类似神经毒剂的干扰。此外，该生物传感器具有很高的可重复使用性（每次传感事件的灵敏度平均降低0.3%）、稳定性（1000 s以上阳极电流信号保留90%）、寿命（8周后保留70%的灵敏度），以及在实际土壤和水样中选择性检测OP的能力。因此，这项工作提出了一种可扩展的印刷石墨烯制造技术，可用于制造适用于现场应用的OP生物传感器，以及更普遍地说，可用于可穿戴或一次性传感范例的低成本生物传感器测试条。
Solution phase printing of graphene-based electrodes has recently become an attractive low-cost, scalable manufacturing technique to create in-field electrochemical biosensors. Here, we report a graphene-based electrode developed via inkjet maskless lithography (IML) for the direct and rapid monitoring of triple-O linked phosphonate organophosphates (OPs); these constitute the active compounds found in chemical warfare agents and pesticides that exhibit acute toxicity as well as long-term pollution to soils and waterways. The IML-printed graphene electrode is nano/microstructured with a 1000 mW benchtop laser engraver and electrochemically deposited platinum nanoparticles (dia. similar to 25 nm) to improve its electrical conductivity (sheet resistance decreased from similar to 10 000 to 100 Omega/sq), surface area, and electroactive nature for subsequent enzyme functionalization and biosensing. The enzyme phosphotriesterase (PTE) was conjugated to the electrode surface via glutaraldehyde cross-linking. The resulting biosensor was able to rapidly measure (5 s response time) the insecticide paraoxon (a model OP) with a low detection limit (3 nM), and high sensitivity (370 nA/mu M) with negligible interference from similar nerve agents. Moreover, the biosensor exhibited high reusability (average of 0.3% decrease in sensitivity per sensing event), stability (90% anodic current signal retention over 1000 s), longevity (70% retained sensitivity after 8 weeks), and the ability to selectively sense OP in actual soil and water samples. Hence, this work presents a scalable printed graphene manufacturing technique that can be used to create OP biosensors that are suitable for in-field applications as well as, more generally, for low-cost biosensor test strips that could be incorporated into wearable or disposable sensing paradigms.