Metal-Organic Framework-Based Gas Sensors: Structural Engineering for Early Diabetes Diagnosis and Monitoring (SEEDDM)

糖尿病是一个巨大的健康问题，2021年全球有5.37亿病例，每年导致数百万人死亡。到2045年，全球每年用于糖尿病的医疗支出预计将达到8760亿英镑。光谱技术(例如，气相色谱和质谱仪)作为有创血糖血液检测的替代品，仍然主导着用于糖尿病筛查和监测的非侵入性呼气分析市场，然而，这些技术相对昂贵、缓慢、复杂，需要专业技能来使用和解释结果。与这些技术相比，基于纳米材料的传感器(如金属氧化物半导体(MOS))具有简单、灵敏、体积小、易于操作和最低维护要求等优点。然而，大多数基于MOS的传感器需要较高的工作温度(200-500℃)，从而导致高能耗。此外，MOSS只允许对不同气体(如醇和酮)进行有限的区分，如果没有专门的光谱技术，就无法确定这些气体。因此，纳米材料的发展受到了极大的推动。金属有机骨架(MOF)材料具有孔径大小和形状可调、高比表面积和纳米孔结构等优点，便于客体分子扩散到高度有序的骨架中，但其非导电性、稳定性差、气敏机理不明确和复杂等问题仍需解决，因此MOF基电极结构的创新需要进一步探索。SEEDDM项目将汇集UM(马来西亚吉隆坡)在异质结材料结构和建模方面的国际公认的研究人员，以及UOE(英国爱丁堡)在多孔性纳米材料开发方面的专业知识，致力于将导电整体金属-有机框架(MOF)与用于呼吸(挥发性有机化合物)VOC传感的适当水凝胶电解质结合在糖尿病早期诊断和监测应用中。我们的联合方法旨在解决研究挑战(导电整体MOF电极和水凝胶电解质在超低功率和室温环境下工作的协同效应)，以创新廉价、便携和高性能的设备。可以在呼吸中检测到的糖尿病生物标志物是VOCs，其中包括丙酮、异戊二烯、一氧化碳、氨和烷烃。通过与UM的合作，将使用最先进的材料和设备表征技术来了解潜在的机制，这些机制将提高我们制定改进的临床决策的能力，使个性化治疗结合更高水平的自我监测和诊断。这项研究的成功将潜在地缓解NHS在早期糖尿病筛查和监测方面的压力。在成功完成SEEDDM之后，我们的目标是创新一种便携式、非侵入性呼吸分析仪，具有高灵敏度(例如，在室温下检测0.05-3ppm丙酮)、高选择性目标气体(例如酮、酒精)、快速的T90响应时间(当气体检测器从读取的0到全标度气体浓度的90%变化时所消耗的时间)小于60s，以及超过1000个氧化还原循环(&gt；85%湿度)的稳定周期。医疗监测设备和可穿戴健康技术在过去几年中增长迅速(2021年为175亿GB，到2030年为1626亿GB，复合年增长率为28.1%)。因此，SEEDDM不仅将有助于提高英国和马来西亚的医疗研究和创新努力的质量，而且还将加强和刺激医疗行业新技术的发展。

Diabetes is a tremendous health problem with 537 million cases worldwide in 2021 and contributing to millions of deaths each year. The annual global health expenditure on diabetes is expected to reach GBP 876 billion by 2045. Spectroscopic technologies (e.g. gas chromatography and mass spectrometry), alternative to invasive glucose blood testing, still dominate the non-invasive breath analysis market for diabetes screening and monitoring, however, these technologies are relatively expensive, slow, complex and require specialist skills to use and to interpret results. In comparison to those techniques, nanomaterials-based sensors (e.g. metal oxide semiconductor (MOS)) provide advantages such as simple, sensitivity, small size, ease of operation, and minimum maintenance requirements. However, most of the MOS-based sensors require high operating temperatures (200-500 oC) resulting in high energy consumption. Furthermore, MOSs only allow limited discrimination between different gases (e.g. alcohols and ketones) which cannot be determined without specialised spectroscopic techniques. Therefore, the development on the nanomaterials have been motivated. Metal-organic framework (MOF)-based materials are favourable due to their tunable pore sizes and shapes, high surface area, and nanopore structures, which allow easy diffusion of guest molecules into the highly-ordered frameworks, but the problems such as (mostly) their nonconducting characteristic, poor stability, unclarified and complicated gas sensing mechanism need to be solved, thus the innovation of structures for MOF-based electrodes calls for further exploration. The SEEDDM project will bring together internationally recognised researchers in heterojunction-based materials architectures and modelling from UM (Kuala Lumpur, Malaysia) and the expertise of UoE (Edinburgh, UK) in the development of porous nanomaterials to work on the conductive monolith metal-organic framework (MOF) coupled with suitable hydrogel electrolytes for breath (volatile organic compounds) VOC sensing in the applications of early diabetes diagnosis and monitoring. Our joint approach aims to solve the research challenges (synergy effects of conductive monolith MOF electrodes and hydrogel electrolytes to work at ultra-low power and room temperature environment) for the purpose of innovating inexpensive, portable, and high-performance devices. Diabetes biomarkers that could be detectable in breath are VOCs, which include acetone, isoprene, carbon monoxide, ammonia, and alkanes. Through collaboration with UM, state-of-the-art materials and device characterisation techniques will be used to understand the underlying mechanisms which will advance our ability to develop improved clinical decision, making personalised therapies combined increased levels of self-monitoring and diagnostics. The successful of this research will potentially ease the pressure of NHS on early diabetes screening and monitoring.After successfully fulfilling SEEDDM, we aim to innovate a portable, non-invasive breath analyser that exhibits high sensitivity (e.g. 0.05-3 ppm acetone detection at room temperature), high selectivity of target gases (e.g. ketone, alcohol), fast T90 response time (the time consumed when the gas detector changes from reading 0 to 90% of the full scale gas concentration) less than 60s, and stable cycle of more than 1,000 redox cycles (>85% humidity). Medical monitoring devices and wearable health technology have seen rapid growth over the past years (£17.5 billion in 2021 to £162.6 billion by 2030, a CAGR of 28.1%). Therefore, SEEDDM will not only help advance the quality of healthcare research and innovative efforts in the UK and Malaysia, but also strengthen and stimulate the development of new technologies in the healthcare industry.