Au Nanoparticle-Decorated ZnO Microflower-Based Immunoassay for Photoelectrochemical Detection of Human Prostate-Specific Antigen

Abstract

Herein, an in situ amplified photoelectrochemical (PEC) immunoassay with ZnO microflowers (ZnO MFs) decorated with gold nanoparticles (Au NPs) was developed to determine human prostate-specific antigen (PSA) using L-cysteineloaded liposomes for signal amplification. Initially, ZnO MFs with smooth and well-defined morphology were synthesized under hydrothermal conditions. The heterostructured microflowers were formed by depositing Au NPs on ZnO microflowers using trisodium citrate. L-Cysteine (L-Cys)-encapsulated liposomes conjugated with detection antibodies were used to fabricate a sandwiched immunocomplex on a capture antibody-modified microtiter plate in the presence of target PSA. The liposomes were lysed using Triton X-100 to release the encapsulated L-Cys, thereby increasing the photocurrent on Au NP-decorated ZnO MFs. Results indicated that the photoelectrochemical immunoassay displayed good photocurrents to response PSA concentrations from 0.01 to 20 ng mL −1 , and the detection PSA concentration was as low as 0.79 pg mL −1 . Furthermore, the photoelectrochemical immunoassay had good precision, high selectivity, and well-matched accuracy toward target PSA in human serum specimens using the commercialized human PSA ELISA kit as a reference.

Glucose oxidase-encapsulated liposomes for amplified autofluorescence-free immunoassay of a prostate-specific antigen with photoluminescence of CePO4:Tb nanocrystals

“…Liposomes encapsulating GOD were prepared according to a previous work. 30,38,39 Briefly, DPPE (7.5 μmol), DPPC (45 μmol), and cholesterol (45 μmol) were added to a 25 mL round-bottom flask containing 6 mL of chloroform. After dissolving, the solvent was evaporated to dryness using a rotary evaporator under reduced pressure at 45 °C to obtain a thin lipid film.…”

Liposome-Mediated In Situ Formation of Ag3PO4/AgBr/Br-CN Ternary Nanostructures on Photoanodes for Photoelectrochemical Immunoassay

“…Photoelectrochemical (PEC) analysis with the superiority of simple instrumentation and high sensitivity has been explored in biological, medical, and other fields. 1 Traditional PEC sensors always operated by driving the sensing progress with an external electrical power supply, which may complicate the configuration and raise the cost. 2 To fulfill the increasing demand for the analytical device with the characteristics of miniaturization, portability, and low cost, self-powered PEC sensors driving the sensing system by light irradiation have attracted extensive attention.…”

Bioinspired Surface Modification of Graphene-Based Hybrids as Nanozyme Sensors for Simultaneous Detection of Dopamine and Uric Acid

“…In comparison with the single-component nanomaterials, hybrid nanomaterials stand out due to their particular structure and synergistic effect. − Cobalt monoxide (CoO), a typical p-type semiconductor, is a promising nanozyme due to the narrow band gap, environmental friendliness, and reversible redox couple of Co 3+ /Co 2+ . Although critical breakthroughs of CoO-based nanomaterials have been realized, some decisive challenges, such as insufficient electron transfer and prone agglomeration of CoO nanoparticles, might depress the catalytic capability and hinder the wide application .…”