Double-Amplified Electrochemiluminescence Immunoassay Sensor for Highly Sensitive Detection of CA19-9 Using a Ternary Semiconductor CdSSe.

In this paper, an electrochemiluminescence (ECL) immunosensor for ultrasensitive detection of CA19-9 was constructed using ternary compound CdSSe nanoparticles as ECL emitter. The immunosensor employs Cu2S and gold-doped diindium trioxide (Au-In2O3) nanocubes as coreaction accelerators to achieve a double-amplification strategy. In general, a hexagonal maple leaf-shaped Cu2S with a large surface area was selected as the template, and the in situ growth of CdSSe on its surface was achieved using a hydrothermal method. The presence of Cu2S not only inhibited the aggregation of CdSSe nanoparticles to reduce their surface energy but also acted as an ECL cathode coreaction promoter, facilitating the generation of SO4•-. Consequently, the ECL intensity of CdSSe was significantly enhanced, and the reduction potential was significantly lower. In addition, the template method was employed to synthesize Au-In2O3 nanocubes, which offers the advantage of directly connecting materials with antibodies, resulting in a more stable construction of the immunosensor. Furthermore, In2O3 serves as a coreaction promoter, enabling the amplification strategy for ECL intensity of CdSSe, thus contributing to the enhanced sensitivity and performance of the immunosensor. The constructed immunosensor exhibited a wide linear range (100 µU mL-1 to 100 U mL-1) and a low detection limit of 80 µU mL-1, demonstrating its high potential and practical value for sensitive detection of CA19-9.

Polyacrylic acid/polyethylene glycol hybrid antifouling interface for photoelectrochemical immunosensing of NSE based on ZnO/CdSe.

In this paper, a novel photoelectrochemical (PEC) immunosensor based on ZnO/CdSe semiconductor composite material was constructed to detect neuron-specific enolase (NSE) in a super-sensitive and quantitative way. The antifouling interface composed of polyacrylic acid (PAA) and polyethylene glycol (PEG) can prevent non-specific proteins from adhering to the electrode surface. As an electron donor, ascorbic acid (AA) can increase the photocurrent's stability and intensity by clearing away photogenerated holes. Because of the specific recognition between antigen and antibody, the quantitative detection of NSE can be achieved. The PEC antifouling immunosensor based on ZnO/CdSe has a wide linear range (0.10 pg mL-1-100 ng mL-1) and a low detection limit (34 fg mL-1), which has potential application in the clinical diagnosis of small cell lung cancer.

Polyacrylic acid/polyethylene glycol hybrid antifouling interface for photoelectrochemical immunosensing of CYFRA 21-1 based on TiO2/PpIX/Ag@Cu2O composite.

A photoelectrochemical (PEC) transducer based on composite TiO2/PpIX/Ag@Cu2O was prepared for the detection of CYFRA 21-1. TiO2 nanomaterials were synthesized by hydrothermal method. TiO2/PpIX/Ag@Cu2O composites were obtained by combining protoporphyrin Ⅸ (PpIX) molecules and Ag@Cu2O on TiO2. This composite material has strong absorption in visible light region and excellent photoelectric chemical properties. Ascorbic acid (AA) is a good electron donor, which can remove photogenerated holes in liquid environment to inhibit the recombination of photogenerated electrons and hole pairs, thus enhancing the photocurrent and improving its stability. The results showed that the sensor can quantitatively test CYFRA 21-1 in the range of 0.1 pg/mL∼100 ng/mL. The photoelectric chemical sensor has the advantages of high sensitivity, low detection line limit and wide linear range.

Cu2O@PdAg-quenched CdS@CeO2 heterostructure electrochemiluminescence immunosensor for determination of prostate-specific antigen.

Based on the resonance energy transfer between CdS@CeO2 and Cu2O@PdAg, a quenching immunosensor for sensitive detection of prostate specific antigen (PSA) was constructed. The CdS@CeO2 heterostructure was obtained by in situ growth of CeO2 particles on the surface of CdS nanorods, and stable cathodic ECL emission was achieved using K2S2O8 as coreactant. Cu2O@PdAg was composed of Cu2O with tetradecahedral structure and bimetallic PdAg nanospheres and has a UV-V is absorption range between 600 and 800 nm. It overlaps with the ECL emission spectrum of CdS@CeO2, realizing the effective quenching of the ECL signal, which provides feasibility for subsequent practical application. The immunosensor exhibited good linearity in the concentration range 10 fg·mL-1 ~ 100 ng·mL-1, with a detection limit of 5.6 fg·mL-1. In sample analysis, the recoveries were 99.8-101%, and the relative standard deviation (RSD) was 0.85-1.6% showing great potential and development value for the sensitive detection of prostate cancer.

The sustained-release behavior and in vitro and in vivo transfection of pEGFP-loaded core-shell-structured chitosan-based composite particles.

Novel submicron core-shell-structured chitosan-based composite particles encapsulated with enhanced green fluorescent protein plasmids (pEGFP) were prepared by complex coacervation method. The core was pEGFP-loaded thiolated N-alkylated chitosan (TACS) and the shell was pH- and temperature-responsive hydroxybutyl chitosan (HBC). pEGFP-loaded TACS-HBC composite particles were spherical, and had a mean diameter of approximately 120 nm, as measured by transmission electron microscopy and particle size analyzer. pEGFP showed sustained release in vitro for >15 days. Furthermore, in vitro transfection in human embryonic kidney 293T and human cervix epithelial cells, and in vivo transfection in mice skeletal muscle of loaded pEGFP, were investigated. Results showed that the expression of loaded pEGFP, both in vitro and in vivo, was slow but could be sustained over a long period. pEGFP expression in mice skeletal muscle was sustained for >60 days. This work indicates that these submicron core-shell-structured chitosan-based composite particles could potentially be used as a gene vector for in vivo controlled gene transfection.