Background

One of the newly developed two-dimensional (2D) materials, MXenes Quantum dots (MQDs) has become a hot topic in materials science over the past ten years. Their potential in fluorescent sensing applications has also gained a lot of attention after the recognition of their distinctive features.

Aim of review

The review signifies the understanding of the synthesis, mechanism, and surface engineering of MQDs for their application as fluorescence sensors.

Findings

The MQDs are prepared by simple top-bottom, bottom-up, and advanced microwave approaches. The mechanism is based on quenching which involves Forster Resonance Energy Transfer (FRET), Inner Filter Effect (IFE), or Photo Induced Electron Transfer (PET) in a broad range of sensing applications. However, sometimes a new analyte is added to recover the fluorescence quenching. Doping with a heteroatom (N, P, S or metal atoms) and co-doping (N-P, N-S, N-, Pt, etc.) has been frequently used to overcome the drawbacks of MQDs such as aggregation, oxidation, and low quantum yield. MQDs modification can be realized by covalent bonding, aryl diazonium chemistry, or non-covalent interactions. Moreover, surface defects are removed to enhance the Photoluminescence Quantum Yield (PLQY) by passivation. However, overcoming the challenges of MQDs synthesis restricted to Ti, detail sensing mechanistic study, and advancement in surface engineering (modification and passivation) could lead to future highly efficient and vast MQDs sensors applications.

中文翻译：

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用于光学金属传感器设计的 MXene 量子点表面工程

背景

MXenes 量子点（MQD）是新开发的二维（2D）材料之一，在过去十年中已成为材料科学的热门话题。在认识到其独特特征后，它们在荧光传感应用中的潜力也引起了广泛关注。

审查目的

该综述标志着对 MQD 作为荧光传感器应用的合成、机制和表面工程的理解。

发现

MQD 是通过简单的自上而下、自下而上和先进的微波方法制备的。该机制基于淬灭，涉及广泛的传感应用中的福斯特共振能量转移 (FRET)、内滤光效应 (IFE) 或光诱导电子转移 (PET)。然而，有时会添加新的分析物来恢复荧光猝灭。杂原子（ N、P、S或金属原子）掺杂和共掺杂（NP、NS、N-、Pt等）已被频繁用于克服MQD的缺点，例如聚集、氧化和低量子数屈服。MQD 修饰可以通过共价键合、芳基重氮化学或非共价相互作用来实现。此外，去除表面缺陷以增强光致发光钝化的量子产率 (PLQY)。然而，克服仅限于 Ti 的 MQD 合成挑战、详细传感机制研究以及表面工程（改性和钝化）的进步可能会带来未来高效和广泛的 MQD 传感器应用。