摘要
Highly luminescent upconversion nanoparticles （UCNPs） with small sizes are highly desirable for bioapplications. A facile in situ cation exchange strategy has been developed to greatly enhance the UC luminescence of hexagonal phase NaYF4 NPs while maintaining their small particle size and shape. Via a cation exchange treatment by hot-injecting Gd3＋ precursors into the as-prepared NPs solution without pre-separation, the naked-eye visible UC emission of the NPs was enhanced about 29 times under 980 nm near infrared （NIR） excitation with unchanged particle size. The cation exchange process was further demonstrated for the case of NaYF4 nanorods （NRs）. After the cation exchange, the nanorod was broken into two NPs with stronger emission. The cation exchanged hydrophobic UCNPs were further encapSulated with poly（amino acid） and successfully applied for targeted cancer cell UC luminescence imaging.
有小尺寸的高度光的 upconversion nanoparticles (UCNP ) 为 bioapplications 是高度合乎需要的。在 situ 阳离子交换策略灵巧的 A 被开发了极大地提高六角形的阶段 NaYF 的 UC 光 < 潜水艇 class= “ a-plus-plus ” > 4 </sub> NP 当维持他们的小粒子尺寸和形状时。经由由热注射的 Gd 的一个阳离子交换处理 < 啜 class= “ a-plus-plus ” >3+ 位 </sup> 先锋进没有分离前的同样准备的 NP 答案， NP 的裸体眼睛的可见 UC 排放在 980 nm 下面被提高大约 29 次近红外线(NIR ) 有未改变的粒子尺寸的刺激。阳离子交换过程进一步为 NaYF 的盒子被表明 < 潜水艇 class= “ a-plus-plus ” > 4 </sub> nanorods (NR ) 。在阳离子交换以后， nanorod 与更强壮的排放被分解为二 NP。阳离子交换了恐水病的 UCNP 进一步被包含与 poly (氨基酸) 并且成功地申请了指向的癌症房间 UC 光成像。
