Hybrid Graphene-Metallic Optofluidic Nanostructures for the Point-of-Care Detection of Illicit Drugs and Biological Agents

加拿大及时需要能够超灵敏、快速和现场检测化学和生物制剂的传感技术，例如生物恐怖主义制剂、爆炸物或非法药物和体液中的致病菌。目前还没有商业技术能够就地、及时地检测这些分析物。目前的检测技术需要昂贵和劳动密集型的程序，以防止潜在的使用者，如执法人员、医务人员或士兵在使用时进行检测。*支持表面等离子的金属纳米结构，如金属纳米孔阵列，已被证明是生物传感器的有力竞争者，在生物分子相互作用的无标记检测方面具有明显的优点。我们最近开发了基于金属流动纳米孔的光流控纳米结构传感器，能够在低于临床尿路感染诊断阈值的浓度下检测人类尿液中的卵巢癌生物标志物和致尿性大肠埃希菌。*尽管光流控纳米结构具有生物传感器的潜力，但有三个主要障碍限制了其作为生物传感器的性能：(I)在流过操作中机械稳定性差，(Ii)使用具有低于标准光子特性的金属来构建纳米结构，以及(Iii)它们的操作限于可见光谱范围。最近发表在《科学》和《自然光子学》上的科学突破表明，石墨烯可以支持中红外和太赫兹频率的表面等离子体。此外，石墨烯还具有优异的力学性能。*拟议的研究旨在通过三个不同的目标开发具有优异性能和灵敏度的新一代石墨烯-金属纳米结构生物传感器：(1)探索和开发混合石墨烯-金属光流控纳米结构(BIO)传感器；(2)研究纳米结构的关键光学和机械特性与流动条件下相应的灵敏度之间的结构-性能关系；以及(3)研究N-杂环卡宾作为功能化试剂在酸性介质(pH和lt；2)和非法药物(即阿片类药物)中实现细菌检测。这些传感器将通过提供以下优势来推进最先进的技术：(A)使用具有优异光子性能的金属(金除外)；(B)更好的机械稳定性和在太赫兹频率下的操作；以及(C)通过促进分析物的活性浓度，如带电分子、蛋白质和细菌，提高灵敏度。*该项目将培养3名博士、3名硕士和4名本科生，他们将获得用于(生物)传感、医学诊断和分析化学研发行业的理论、实验和计算建模技能。

There is a timely need in Canada for sensing technologies that allow ultrasensitive, rapid and in situ detection of chemical and biological agents such as bioterrorism agents, explosives, or illicit drugs and pathogenic bacteria in bodily fluids. There is no commercial technology capable of detecting those analytes, in situ, and in timely fashion. Current detection technologies require costly and labor-intensive procedures that prevent potential users, such as law enforcement officers, (para)medics or soldiers, to perform detection at the point of use.***Metallic nanostructures that support surface plasmons, such as metallic nanohole arrays, have demonstrated to be great contenders as biosensors, holding distinct merits for the label-free detection of bio-molecular interactions. We have very recently developed optofluidic nanostructured sensors based on metallic flow-through nanoholes, that enable the detection of ovarian cancer biomarkers and uropathogenic E. coli in humane urine - the bacteria responsible for urinary tract infections (UTI) - at concentrations below the clinical threshold for UTI diagnosis. ***Despite their potential as biosensors, three major obstacles limit the performance of optofluidic nanostructures as biosensor: (i) poor mechanical stability in flow-through operation, (ii) the use of metals with subpar photonic characteristics to build the nanostructures, and (iii) their operation is limited to the visible range of the spectrum. Recent scientific breakthroughs, published in Science and Nature Photonics, have demonstrated that graphene can support surface plasmons at mid-infrared and THz frequencies. In addition, graphene also owns outstanding mechanical properties. ***The proposed research aims to develop a new generation of hybrid graphene-metallic nanostructured biosensors with superior properties in terms of performance and sensitivity, through three distinct objectives: (1) the exploration and development of hybrid graphene-metallic optofluidic nanostructured (bio)sensors; (2) investigation of structure-performance relations that correlate key optical and mechanical characteristics of the nanostructures with consequential sensitivity in flow-through conditions; and (3) investigate the utilization of N-heterocyclic carbenes as functionalization agents to achieve detection of bacteria in acidic pH media (pH < 2) and illicit drugs (i.e. opioids). These sensors will advance the state-of-the-art by providing the following advantages: (a) the use of metals with superior photonic properties (other than gold); (b) better mechanical stability and operation at THz frequencies; and (c) enhanced sensitivity by facilitating the active concentration of analyte, such as charged molecules, proteins and bacteria. ***The program will train 3 PhD, 3 MSc and 4 undergraduate students, who will acquire theoretical, experimental and computational modelling skills used in the (bio)sensing, medical diagnostics and analytical chemistry R&D industry.