稀土上转换发光纳米探针用于潜指纹中可卡因的检测

Detection of Exogenous Compounds in Latent Fingerprints Based on Aptamers-functionalized Upconversion Nanoparticles

结合核酸适配体和稀土掺杂上转换纳米材料的优势,建立了一种潜指纹中外源性物质检测的新方法。Zeta电位、紫外吸收光谱和发光光谱表明核酸适配体成功修饰到上转换颗粒表面而且没有影响颗粒的发光性质。对含有不同量可卡因的指纹进行检测,在指纹中可卡因含量为0.5μg时仍能呈现出较强的发光强度。该方法能够通过潜指纹成像提供光学信号,实现潜指纹中外源性物质的检测,而且适用于不同人和不同基底上指纹的检测,具有简便、检测灵敏度高、适用性广等优点,对身份认证、刑事侦查和医疗诊断有重要意义。

A novel imaging strategy for the detection of exogenous compounds in latent fingerprints（LFPs）was developed based on aptamers-functionalized upconversion nanoparticles（UCNPs）.In this work,UCNPs were first capped with polyacrylic acid（PAA）（designated as PAA-UCNPs）to make it water-soluble and functional groups were introduce to its surface for further conjugation with biomolecules.Then,PAA-UCNPs was functionalized with cocaine binding aptamer（designated as UCNPs-CBA）to form the final imaging probe via amide bond.The zeta potentials,UV-Vis absorption spectra and upconversion luminescence spectra were used to confirm the above functionalization steps.LFPs with different loadings of cocaine were collected on glass slides and incubated with UCNPs-CBA.Under NIR light excitation,LFPs with cocaine showed strong luminescence while LFPs without cocaine showed nothing,indicating it was the recognition of cocaine by UCNPs-CBA that led to the imaging of LFPs.In addition,the detection limit of cocaine in LFPs was determined to be as low as 0.5μg.Furthermore,LFPs from different people and on different surfaces were both developed successfully with UCNPs-CBA nanoconjugate,which showed the great generality of this imaging strategy.It is noteworthy that this strategy can also be applied to other exogenous compounds detection in LFPs by simply using other types of aptamers.Additionally,no expensive or complicated instrumentations were used in this experiment and all the operations are easy to handle,thus demonstrating the great practical prospects of this method.This novel imaging strategy for the detection of exogenous compounds in LFPs is expected to find applications in individual identification,forensic investigation,and medical diagnosis.