Fluorescence immunosensor based on p-acid-encapsulated silica nanoparticles for tumor marker detection

Abstract

A novel, simple and highly sensitive amplified fluorescence label-free immunosensor by using p-acid-encapsulated silica nanomaterials has been developed for the first time. 4,4'-(2,5-Dimethoxy-1,4-phenylene)bis(ethyne-2,1-diyl)dibenzoic acid (p-acid) and p-acid-encapsulated silica were prepared, and characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance, ultraviolet visible spectroscopy (UV-vis) and fluorescence spectroscopy. In layer-by-layer self-assembling processes using (3-aminopropyl)triethoxysilane, p-acid@SiO(2) was assembled on the glass substrate. Antibody was immobilized on the surface of p-acid@SiO(2) with N,N'-carbonyldiimidazole. The functional nanomaterials present good analytical properties with a calibration range of 0.1-100 ng mL(-1), and allow the detection of carcinoembryonic antigen (CEA) at a concentration as low as 0.04 ng mL(-1). What is important is that the as-synthesized p-acid@SiO(2) nanomaterials could be further extended for the detection of other biomarkers or biocompounds.

Fluorescent Silica Nanoparticles for Medical Imaging

“…Many cancer cells overexpress specialized receptors which researchers have been able to take advantage for particle functionalization and cell targeting. 27,98 FSNP surface functionalization with folic acid, through amine reactive binding, increases the bioconjugation capability and the aqueous dispersibility of the NPs for intracellular. 99 Folate receptors active in the brain, ovary, kidney, breast and lungs 31,34,37 will uptake folate-conjugated NPs when possible through endocytosis (demonstrated through SCLM studies).…”

Synthesis, characterization of a novel phenyleneethynylene derivative and application in a fluorescence DNA sensor

“…The procedure of p-acid's synthesis is shown on Scheme 1, which was prepared according to the published literature 11,[20][21][22] with slight modication.…”

“…In this paper, p-acid was synthesized by Heck-Cassar-Sonagashira-Hagihara cross coupling reaction. 11,[20][21][22] In addition, SiO 2 has always been a famous base material for it is hydrophilic, biocompatible, not subject to microbial attack, and no swelling or porosity change occurs with changes in pH. Therefore, to demonstrate the application of p-acid, p-acid@-SiO 2 was synthesized as an effective and highly stable uorescence probe for reporter-DNA (S 3 ) in LBL self-assembling processes.…”

1,1'-Carbonyldiimidazole-copper nanoflower enhanced collapsible laser scribed graphene engraved microgap capacitive aptasensor for the detection of milk allergen

“…1,1′-Carbonyldiimidazole (CDI) is an organic chemical with highly reactive carboxylating agent that contains two acylimidazole leaving groups with hydroxylated surfaces for bioconjugation of an analyte and often used as a linker in most biosensor surface construction 29 – 31 . The imidazole functional groups of CDI exhibit a strong interaction with the copper atom, forming charge-transfer complexes 32 .…”