Understanding the bonding mechanisms of organic molecules deposited on graphene for biosensing applications.
Understanding the bonding mechanisms of organic molecules deposited on graphene for biosensing applications.
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DOI：
10.1063/5.0064136
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发表时间：
2021-11
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影响因子：
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通讯作者：
Elizabeth J Legge;Muhammad Munem Ali;H. Abbasi;B. Reed;B. Brennan;L. Matjačić;Z. Tehrani;V. Stolojan;S. Silva;O. Guy;A. Pollard
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文献类型：
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作者：
Elizabeth J Legge;Muhammad Munem Ali;H. Abbasi;B. Reed;B. Brennan;L. Matjačić;Z. Tehrani;V. Stolojan;S. Silva;O. Guy;A. Pollard
石墨烯是用于生物传感器的理想材料，这是由于用于多个键合位点的大表面积、允许高灵敏度的高电导率以及在制造的传感器装置中提供耐久性的高拉伸强度。对于石墨烯作为生物传感平台的成功，选择性必须通过特定化学基团的功能化来实现。然而，在功能化之后仍然必须保持器件性能和传感器灵敏度，这可能具有挑战性。我们比较了苯胺和1，5-二氨基萘功能化方法的化学气相沉积生长的石墨烯，都用于获得修饰有胺基的石墨烯，这是需要高选择性抗体生物受体的表面附着。通过原子力显微镜（AFM），拉曼光谱，和飞行时间二次离子质谱成像的共定位区域，化学，厚度和覆盖的功能团结合到石墨烯表面已全面分析。我们证明了使用AFM的功能化石墨烯的改性，这出乎意料地表明共价键合的官能团的去除，导致具有减少的无序的“恢复的”石墨烯结构，用拉曼光谱证实。这种去除解释了在机械应变或化学反应后在来自官能化石墨烯的其他研究的拉曼光谱中观察到的ID/IG比的降低，并揭示了恢复到非官能化石墨烯结构的可能性。通过这项研究，推荐了优选的功能化过程，以保持石墨烯作为生物传感器的性能。
Graphene is an ideal material for biosensors due to the large surface area for multiple bonding sites, the high electrical conductivity allowing for high sensitivity, and the high tensile strength providing durability in fabricated sensor devices. For graphene to be successful as a biosensing platform, selectivity must be achieved through functionalization with specific chemical groups. However, the device performance and sensor sensitivity must still be maintained after functionalization, which can be challenging. We compare phenyl amine and 1,5-diaminonaphthalene functionalization methods for chemical vapor deposition grown graphene, both used to obtain graphene modified with amine groups-which is required for surface attachment of highly selective antibody bio-receptors. Through atomic force microscopy (AFM), Raman spectroscopy, and time-of-flight secondary ion mass spectrometry imaging of co-located areas, the chemistry, thickness, and coverage of the functional groups bound to the graphene surface have been comprehensively analyzed. We demonstrate the modification of functionalized graphene using AFM, which unexpectedly suggests the removal of covalently bonded functional groups, resulting in a "recovered" graphene structure with reduced disorder, confirmed with Raman spectroscopy. This removal explains the decrease in the ID/IG ratio observed in Raman spectra from other studies on functionalized graphene after mechanical strain or a chemical reaction and reveals the possibility of reverting to the non-functionalized graphene structure. Through this study, preferred functionalization processes are recommended to maintain the performance properties of graphene as a biosensor.