title: An aptamer-based biosensor for sensitive thrombin detection with phthalocyanine@SiO2 mesoporous nanoparticles.
abstract: Silica nanoparticles, with entrapped hydrophobic photosensitizer tetra-α-(2, 4-di-tert-butylphenoxy)-phthalocyaninato zinc (ZnPc(OAr)4), were synthesized by hydrolyzing triethoxyvinylsilane (TEVS) and 3-amino propyl triethoxysilane (APTES). The as-prepared nanoparticles, which were highly monodispersed spheres (about 100 nm), exhibited strong Q-band absorption of ZnPc(OAr)4 centered at 701 nm. The aqueous solubility of ZnPc(OAr)4 encapsulated in silica nanoparticles was obviously improved. The nanoparticles efficiently generated singlet oxygen ((1)O2) both in organic and aqueous solutions after being irradiated at suitable wavelength. The resulting (1)O2 then initiated chemiluminescence (CL) by reacting with a methyl cypridina luciferin analog (MCLA). Based on the photoinduced CL, a sensitive aptamer-based sandwich-type sensor was presented to detect human thrombin. Thrombin was first attached to Pc@SiO2 via secondary aptamer, and then they were collected, for CL determination, by beads with primary aptamer. The proposed approach, which was highly selective with a low detection limit of 80 pmol/L, minimized the nonspecific adsorption. Such an aptamer-based biosensor is feasible in screening biomarkers in complex matrices at ultratrace levels.
authors.affiliation: Institute of Research on Functional Materials, Cancer Metastasis Alert and Prevention Center, Fuzhou University, Fuzhou 350108, China; College of Chemistry and Chemical Engineering, Fuzhou University, Fuzhou 350108, China.
authors.forename: Zhou
authors.initials: Z
authors.lastname: Jiang
authors.forename: Tingting
authors.initials: T
authors.lastname: Yang
authors.forename: Minyan
authors.initials: M
authors.lastname: Liu
authors.forename: Yanli
authors.initials: Y
authors.lastname: Hu
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry; D015374:Biosensing Techniques / Q000379:methods*; D006046:Gold / Q000737:chemistry; D006801:Humans; D007211:Indoles / Q000737:chemistry; D054833:Isoindoles; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*; D009841:Oligonucleotides / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013917:Thrombin / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D052157:Aptamers, Nucleotide; D007211:Indoles; D054833:Isoindoles; D009841:Oligonucleotides; D006046:Gold; D012822:Silicon Dioxide; D013917:Thrombin; C013647:phthalocyanine
keywords: Chemiluminescence; Silica nanoparticle; Tetra-α-(24-di-tert-butylphenoxy)-phthalocyaninato zinc; Thrombin