Semiconducting nanoparticles (NPs) find applications in many fields, with a recent focus on medicine and biology. Functionalization of the surface of NPs is necessary, and one of the most commonly employed techniques is ligand exchange (LE). In this paper, the study of pH influence on LE reaction for different types of cadmium-based NPs (quantum dots, nanorods, and nanoplates) is presented. Hydrophobic NPs were transferred to the non-organic medium by functionalization with d-penicillamine (DPA). The LE procedure was conducted at four different pH levels (4, 7, 9, and 11), and obtained hydrophilic NPs were dispersed in phosphate buffer. Results show that the most effective procedure resulted from a reaction carried at pH = 4; however, NPs with higher photoluminescence intensity were obtained when pH = 11 was used. Comparable emission was achieved from samples at pH = 4 and pH = 9. The least effective transfer, resulting in unstable NPs, occurred when the procedure was conducted at pH = 7.

半导体纳米颗粒（NPs）在许多领域都有应用，最近的重点是医学和生物学。NP表面的功能化是必要的，最常用的技术之一是配体交换（LE）。本文介绍了pH对不同类型的镉基纳米颗粒（量子点，纳米棒和纳米板）的LE反应的影响的研究。通过用d官能化将疏水性NPs转移到非有机介质中-青霉胺（DPA）。LE程序在四个不同的pH值（4、7、9和11）下进行，并将获得的亲水性NP分散在磷酸盐缓冲液中。结果表明，最有效的方法是在pH = 4的条件下进行的；但是，当使用pH = 11时，可以获得具有更高的光致发光强度的NP。从pH = 4和pH = 9的样品获得了可比较的发射。当在pH = 7的条件下进行操作时，发生最不有效的转移，导致NP不稳定。