On-chip droplet analysis and cell spheroid screening by capillary wrapping enabled shape-adaptive ferrofluid transporters.

Non-invasive droplet manipulation with no physical damage to the sample is important for the practical value of manipulation tools in multidisciplinary applications from biochemical analysis and diagnostics to cell engineering. It is a challenge to achieve this for most existing photothermal, electric stimuli, and magnetic field-based technologies. Herein, we present a droplet handling toolbox, the ferrofluid transporter, for non-invasive droplet manipulation in an oil environment.

A label-free immunosensor for the sensitive detection of hepatitis B e antigen based on PdCu tripod functionalized porous graphene nanoenzymes.

Nanomaterials with enzyme properties possess excellent catalytic activity and stability. We prepared new nanoenzymes to construct a label-free electrochemical immunosensor for the detection of hepatitis B e antigen (HBe Ag). In this study, PdCu tripod (PdCu TP) functionalized porous graphene (PG) nanoenzymes (PdCu TPs/PG) were prepared through the in situ reduction of PdCu tripods onto porous graphene.

A Signal Amplification Strategy of CuPtRh CNB-Embedded Ammoniated TiC MXene for Detecting Cardiac Troponin I by a Sandwich-Type Electrochemical Immunosensor.

An early diagnosis of cardiovascular disease is of great importance to patients. Herein, a sandwich-type immunosensor for the detection of cardiac troponin I (cTnI) is prepared by using gold nanoparticles (Au NPs) and a composite (CuPtRh CNBs/NH-TiC) of trimetallic hollow CuPtRh cubic nanobox (CNB)-embedded few-layer ultrathin ammoniated MXene (NH-TiC). The embedding of the CuPtRh CNBs into NH-TiC successfully prevents the restacking of NH-TiC and offers more active sites for catalytic HO reduction, which can effectively increase the current signal of the immunosensor.

Amperometric immunoassay for the carcinoembryonic antigen by using a peroxidase mimic consisting of palladium nanospheres functionalized with glutathione-capped gold nanoparticles on graphene oxide.

A composite nanoenzyme was used in a sandwich-type electrochemical immunoassay for the carcinoembryonic antigen (CEA). Hierarchically porous palladium nanospheres (Pd NPs) were functionalized with glutathione-capped gold nanoparticles (G-Au NPs) and then loaded onto graphene oxide (GO) to obtain a peroxidase mimicking nanoenzyme of type GO-supported G-Au/Pd. The composite can catalyze the oxidation of the substrate tetramethylbenzidine (TMB) by HO to give blue-colored oxidized TMB within only 20 s.

A label-free immunosensor based on PtPd NCs@MoS nanoenzymes for hepatitis B surface antigen detection.

Nowadays, nanomaterials with enzymatic properties have aroused wide interest because of their special advantages, such as catalytic activity, simple preparation method and high stability. We introduced new nanoenzymes to a label-free electrochemical immunosensor for Hepatitis B surface antigen (HBs Ag) detection. In this study, PtPd nanocubes@MoS nanoenzymes (PtPd NCs@MoS) were prepared by loading PtPd nanocubes (PtPd NCs) on molybdenum disulfide nano-sheet (MoS) through in situ redox polymerization.

Sensitive amperometric immunosensor with improved electrocatalytic Au@Pd urchin-shaped nanostructures for human epididymis specific protein 4 antigen detection.

Sensitive detection of early ovarian cancer is imminent for women's health. Human epididymis specific protein 4 antigen (HE4 Ag), as a novel tumor marker, has good specificity and sensitivity in ovarian cancer markers, especially for the detection of early ovarian cancer. In this work, a novel and ultrasensitive sandwich-type amperometric electrochemical immunosensor was constructed using amine modified graphene supported gold nanorods (Au NRs/NH-GS) as a sensor platform and core-shell Au@Pd urchin-shaped nanostructures (Au@Pd USs) as a label of the secondary antibodies (Ab, Au@Pd USs-Ab) to realize the quantitative determination of HE4 Ag.

Label-free immunosensors based on a novel multi-amplification signal strategy of TiO-NGO/Au@Pd hetero-nanostructures.

A label-free electrochemical immunosensor for quantitative detection of human epididymis specific protein 4 antigen (HE4 Ag) was developed by a novel multi-amplification signal system. The multi-amplification signal system was formed by loading bimetallic Au@Pd holothurian-shaped nanoparticles (Au@Pd HSs) on titanium oxide nanoclusters functionalized nitrogen-doped reduced graphene oxide (TiO-NGO). The Au@Pd HSs were obtained via seed-mediated approach with in-situ grown palladium nanoarms on gold nanorods (Au NRs) surfaces, which possessed good electrocatalysis for hydrogen peroxide (HO) reduction and excellent biocompatibility.

A label-free electrochemical immunosensor based on the novel signal amplification system of AuPdCu ternary nanoparticles functionalized polymer nanospheres.

A sensitive label-free electrochemical immunosensor was designed using a novel signal amplification system for quantitative detecting hepatitis B surface antigen (HBsAg). Nitrogen-doped graphene quantum dots (N-GQDs) supported surfactant-free AuPdCu ternary nanoparticles (AuPdCu/N-GQDs), which featured with good conductivity and excellent catalytic properties for the reduction of hydrogen peroxide (HO), was synthesized by a simple and benign hydrothermal procedure. At the same time, the electroactive polymer nanospheres (PS) was synthesized by infinite coordination polymers of ferrocenedicarboxylic acid, which could play as carrier and electronic mediator to load AuPdCu/N-GQDs.