ABSTRACT
The ultrasensitive detection of hepatitis C virus (HCV) nucleic acid is crucial for the early diagnosis of hepatitis C. In this study, by combining Ag@Au core/shell nanoparticle (Ag@AuNP)-based surface-enhanced Raman scattering (SERS) tag with hybridization chain reaction (HCR), a novel SERS-sensing method was developed for the ultrasensitive detection of HCV nucleic acid. This SERS-sensing system comprised two different SERS tags, which were constructed by modifying Ag@AuNP with a Raman reporter molecule of 4-ethynylbezaldehyde, two different hairpin-structured HCR sequences (H1 or H2), and a detection plate prepared by immobilizing a capture DNA sequence onto the Ag@AuNP layer surface of the detection wells. When the target nucleic acid was present, the two SERS tags were captured on the surface of the Ag@AuNP-coated detection well to generate many "hot spots" through HCR, forming a strong SERS signal and realizing the ultrasensitive detection of the target HCV nucleic acid. The limit of detection of the SERS-sensing method for HCV nucleic acid was 0.47 fM, and the linear range was from 1 to 105 fM.
Subject(s)
Hepatitis C , Metal Nanoparticles , Nanoparticles , Nucleic Acids , Humans , Hepacivirus/genetics , Spectrum Analysis, Raman/methods , GoldABSTRACT
Herein, we have designed and synthesized a quinolinyl-AIE photosensitizer (TPE-4QL+) with an alternative elevated intersystem crossing (ISC) rate, which exhibits not only highly efficient photosensitivity but also high tumor cell specificity and an excellent mitochondrial targeting ability. In vitro experiments indicate that using TPE-4QL+ as a photosensitizer can induce a series of tumor cells to die with a low dose of radiation, but with no obvious toxicity to normal cells. The in vivo studies on a mouse model bearing a subcutaneous 4T1 xenograft also show that TPE-4QL+ can be used with high efficiency as a photosensitizer in PDT.