Upconversion nanoparticles (UCNPs) are widely recognized exogenous contrast agents for bioimaging. Swept source optical coherence tomography (SSOCT) is a non-invasive imaging tool commissioned for cross-sectional imaging of the biological sample. We present polymerically modified UCNPs as a potential contrast agent for SSOCT. In this communication, functionalized NaYF₄: Ho³⁺/Yb³⁺ UCNPs were synthesized for more bioavailability with a coating of two different polymers namely, polyethylene glycol (PEG) and polyvinylpyrrolidone (PVP). Time-dependent diffusion dynamics of functionalized UCNPs were performed in-vivo with a mice model. Imaging was performed with both inactive and excited UCNPs. A separate optical system was developed with an amplitude modulated 980 nm laser source to excite UCNPs. UCNPs with PVP coating shows better results compared to others in terms of increase of scattering coefficients and contrast-to-noise ratio. The complete system is designed with purpose to enhance imaging contrast of tissue at molecular level with further possible extension as a theranostics system for tumor imaging during photodynamic therapy.

上转换纳米颗粒（UCNPs）是公认的生物成像外源性造影剂。扫频光学相干断层扫描（SSOCT）是一种非侵入性成像工具，已委托对生物样品进行截面成像。我们提出聚合修饰的UCNPs作为SSOCT的潜在造影剂。在此通讯中，功能化的NaYF ₄：Ho ³⁺ / Yb ³⁺合成了UCNP，具有更高的生物利用度，并涂有两种不同的聚合物，即聚乙二醇（PEG）和聚乙烯吡咯烷酮（PVP）。功能化的UCNPs的时间依赖性扩散动力学是在小鼠模型中进行的。使用无活性和兴奋性UCNPs进行成像。开发了一个单独的光学系统，该系统具有调幅980 nm激光源以激发UCNP。具有PVP涂层的UCNP在散射系数和对比度噪声比的增加方面显示出比其他更好的结果。设计完整的系统的目的是增强分子水平上的组织成像对比度，并进一步扩展其作为光动力学治疗过程中肿瘤成像的治疗学系统。