Latent fingerprints (LFPs) are highly specific to individuals, and LFP imaging has played an important role in areas such as forensic investigation and law enforcement. Presently, LFP imaging still faces considerable problems, including background interference and destructive and complex operations. Herein, we have designed a background-free, nondestructive, and easy-to-perform method for LFP imaging based on pH-mediated recognition of LFPs by carboxyl group-functionalized Zn₂GeO₄:Mn (ZGO:Mn-COOH) persistent luminescence nanorods (PLNRs). By simply adjusting the pH of the ZGO:Mn-COOH colloid dispersion to a certain acidic range, the negatively charged ZGO:Mn-COOH readily binds to protonated fingerprint ridges via electrostatic attraction. The ZGO:Mn-COOH colloid dispersion can be stored in portable commercial spray bottles, and the LFPs have been easily detected in situ by simply dropping the colloid dispersion on the LFPs. Moreover, since the ZGO:Mn-COOH can remain luminescent after excitation ceases, background color and background fluorescence interference were efficiently removed by simply capturing the luminescent LFP images after the excitation ceased. The entire LFP imaging process can be easily conducted without any destructive or complex operations. Due to the great versatility of the developed method for LFP imaging, clear LFP images with well-resolved ridge patterns were obtained. The designed background-free, nondestructive, and easy-to-perform LFP imaging strategy has great potential for future applications, such as forensic investigations and law enforcement.

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潜在指纹（LFP）高度针对个人，LFP成像在法医调查和执法等领域中发挥了重要作用。目前，LFP成像仍面临相当大的问题，包括背景干扰以及破坏性和复杂的操作。本文中，我们基于羧基官能化的Zn ₂ GeO _4的pH介导的LFP识别，设计了一种无背景，无损且易于执行的LFP成像方法。：Mn（ZGO：Mn-COOH）持久发光纳米棒（PLNRs）。通过简单地将ZGO：Mn-COOH胶体分散体的pH调节到某个酸性范围，带负电荷的ZGO：Mn-COOH容易通过静电吸引与质子化的指纹脊结合。ZGO：Mn-COOH胶体分散液可以存储在便携式商用喷雾瓶中，并且LFP很容易就地检测到只需将胶体分散液滴在LFP上即可。此外，由于ZGO：Mn-COOH在激发停止后仍可保持发光，因此仅通过在激发停止后捕获发光LFP图像即可有效地消除背景色和背景荧光干扰。整个LFP成像过程可以轻松进行，而无需进行任何破坏性或复杂的操作。由于所开发的LFP成像方法的通用性强，因此获得了清晰分辨的具有脊形图案的LFP图像。设计的无背景，无损且易于执行的LFP成像策略在法医学调查和执法等未来应用中具有巨大潜力。

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