Nanoconfined in-situ sampling and extracting switching needle device construction for highly enrichment of polar metabolites in human urine.

Urine, as a non-invasive sampling specimen, offers significant advantages for the diagnosis and treatment of diseases. However, as a water-based matrix, most metabolites in urine are high polarity, which limits the ultrafast extraction and high enrichment of these polar metabolites from urine. Though solvent-based extraction method has demonstrated considerable benefits in extraction rates, the necessity for selecting water-immiscible solvents restricts the extraction of highly polar metabolites. Consequently, there is a pressing need for a rapid extraction method that achieves a high enrichment factor specifically targeting highly polar metabolites in urine. (90) RESULTS: This study is the first attempt to use water-soluble solvent to extract highly polar metabolites from urine. Firstly, a needle device capable of switching between sampling and extracting modes was constructed by utilizing carbon nanofibers/carbon fibers (CNFs/CFs) filled with the needle tip. Under the effect of nanoconfinement, the needle can achieve in-situ ultrafast extraction employing a methanol/water mixture as the nanoconfined extraction solvent. Additionally, the nanodistribution of the extracted solvent within the nanoconfined space enhances the exaction rate and efficiency. By coupling this method with HILIC-LC/MS detection protocol, 33 highly polar metabolites from human urine were simultaneously quantified within 3 min. Following systematic validation, the established method was successfully applied to urine target metabolomics analysis for hepatocellular carcinoma, the potential diagnosis biomarkers were screened out using multiple data processing methods. (130) SIGNIFICANCE: In conclusion, the home-made nanoconfinement effect based in-situ sampling and extracting (NISE) switching needle device demonstrates strong advantages in the highly enrichment and ultrafast analysis of highly polar metabolites in an aqueous matrix, providing a promising tool for clinical disease diagnosis and screening. (44).