Black phosphorus quantum dots (BPQDs) as novel nanomaterials have many potential applications in biomedicine. However, the interaction of BPQDs with proteins and their biological effects and potential risks are still unclear. Here, mucin, which serves biologically as a physical barrier against foreign substances entering tissues, was chosen as a model substrate for studying the adsorption–desorption behavior of BPQDs using surface plasmon resonance sensing and a quartz crystal microbalance with dissipation monitoring. We found that the surface modification of BPQDs with poly(ethylene glycol)-amine (PEG-NH₂) reduces the adsorption rate of the quantum dots but increases their adsorbed amount on the mucin surface. The pH value, ionic strength, and ionic valence also had significant effects on the adsorption behavior of BPQDs. Upon increasing the pH from 2 to 7, the amount of BPQD adsorption decreased from 14.1 to 3.2 ng/cm². A high ionic strength and ionic valence (e.g., Mg²⁺, Al³⁺) also inhibit the surface adsorption of BPQDs. Furthermore, the adsorption–desorption mechanisms of BPQDs on the mucin surface were proposed. The adsorption–desorption behavior under different conditions may be attributed to the steric hindrance of PEG, the electrostatic interaction, and/or charge screening. These findings provide useful insights into the interfacial behavior of BPQDs before they enter the tissues.

中文翻译：

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粘蛋白表面黑色磷量子点的吸附-解吸行为

黑磷量子点（BPQDs）作为新型纳米材料在生物医学中具有许多潜在的应用。但是，BPQD与蛋白质的相互作用及其生物学效应和潜在风险仍不清楚。在这里，粘蛋白在生物学上是作为阻止异物进入组织的物理屏障，因此被选为模型基质，用于通过表面等离振子共振传感和带有耗散监测的石英晶体微量天平研究BPQD的吸附-解吸行为。我们发现用聚（乙二醇）-胺（PEG-NH ₂）降低了量子点的吸附速率，但增加了它们在粘蛋白表面上的吸附量。pH值，离子强度和离子价态也对BPQDs的吸附行为有重要影响。当pH从2增加到7时，BPQD的吸附量从14.1下降到3.2ng / cm ²。高离子强度和离子化合价（例如Mg 2 ⁺，Al ³⁺）还抑制BPQD的表面吸附。此外，提出了BPQDs在粘蛋白表面的吸附-解吸机理。在不同条件下的吸附-解吸行为可能归因于PEG的位阻，静电相互作用和/或电荷筛选。这些发现为BPQD在进入组织之前的界面行为提供了有用的见解。