Combining Upconversion Luminescence, Photothermy, and Electrochemistry for Highly Accurate Triple-Signal Detection of Hydrogen Sulfide by Optically Trapping Single Microbeads.

The detection of hydrogen sulfide (H2S), the third gas signaling molecule, is a promising strategy for identifying the occurrence of certain diseases. However, the conventional single- or dual-signal detection can introduce false-positive or false-negative results, which ultimately decreases the diagnostic accuracy. To address this limitation, we developed a luminescent, photothermal, and electrochemical triple-signal detection platform by optically trapping the synthetic highly doped upconversion coupled SiO2 microbeads coated with metal-organic frameworks H-UCNP-SiO2@HKUST-1 (H-USH) to detect the concentration of H2S. The H-USH was first synthesized and proved to have stable structure and excellent luminescent, photothermal, and electrochemical properties. Under 980 nm optical trapping and 808 nm irradiation, H-USH showed great detection linearity, a low limit of detection, and high specificity for H2S quantification via triple-signal detection. Moreover, H-USH was captured by optical tweezers to realize quantitative detection of H2S content in serum of acute pancreatitis and spontaneously hypertensive rats. Finally, by analyzing the receiver operating characteristic (ROC) curve, we concluded that triple-signal detection of H2S was more accurate than single- or dual-signal detection, which overcame the problem of false-negative/positive results in the detection of H2S in actual serum samples.