Abstract：
Gold nanoclusters are a smart platform for sensing potassium ions (K+). They have been synthesized using bovine serum albumin (BSA) and valinomycin (Val) to protect and cap the nanoclusters. The nanoclusters (Val-AuNCs) produced have a red emission at 616 nm under excitation with 470 nm. In the presence of K+, the valinomycin polar groups switch to the molecule\'s interior by complexing with K+, forming a bracelet structure, and being surrounded by the hydrophobic exterior conformation. This structure allows a proposed fluorometric method for detecting K+ by switching between the Val-AuNCs\' hydrophilicity and hydrophobicity, which induces the aggregation of gold nanoclusters. As a result, significant quenching is seen in fluorescence after adding K+. The quenching in fluorescence in the presence of K+ is attributed to the aggregation mechanism. This sensing technique provides a highly precise and selective sensing method for K+ in the range 0.78 to 8 µM with LOD equal to 233 nM. The selectivity of Val-AuNCs toward K+ ions was investigated compared to other ions. Furthermore, the Val-AuNCs have novel possibilities as favorable sensor candidates for various imaging applications. Our detection technique was validated by determining K+ ions in postmortem vitreous humor samples, which yielded promising results.
摘要：
金纳米团簇是用于感测钾离子(K+)的智能平台。它们是使用牛血清白蛋白（BSA）和缬霉素（Val）合成的，以保护和覆盖纳米簇。所产生的纳米团簇(Val-AuNC)在470nm的激发下在616nm处具有红色发射。在K+的存在下,缬氨酸霉素极性基团通过与K+络合而转换到分子内部，形成手镯结构，并被疏水性外部构象包围。这种结构允许通过在Val-AuNCs亲水性和疏水性之间切换来检测K+的荧光测量方法，诱导金纳米团簇的聚集。因此,在添加K+后,在荧光中观察到显著的猝灭。在K+存在下荧光的猝灭归因于聚集机制。这种传感技术为K+提供了一种高度精确和选择性的传感方法，范围为0.78至8µM，LOD等于233nM。与其他离子相比，研究了Val-AuNC对K离子的选择性。此外，Val-AuNC具有作为各种成像应用的有利传感器候选的新颖可能性。通过确定死后玻璃体液样品中的K离子来验证我们的检测技术，这产生了有希望的结果。
