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 (H 2 S), 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 SiO 2 microbeads coated with metal-organic frameworks H-UCNP-SiO 2 @HKUST-1 (H-USH) to detect the concentration of H 2 S. 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 H 2 S quantification via triple-signal detection. Moreover, H-USH was captured by optical tweezers to realize quantitative detection of H 2 S 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 H 2 S was more accurate than single- or dual-signal detection, which overcame the problem of false-negative/positive results in the detection of H 2 S in actual serum samples.