•The PtPd PNRs were porous and alloy-structured and showed much higher affinity to H2O2.•Colorimetric method for the flux of H2O2 release from living cell was developed using PtPd PNRs as a peroxidase mimetic.•The PtPd PNRs have good stability, and fine biocompatibility which can greatly overcome the intrinsic shortcomings.One-dimensional PtPd porous nanorods (PtPd PNRs) were successfully synthesized through a bromide-induced galvanic replacement reaction between Pd nanowires and K2PtCl6. The PtPd PNRs were porous and alloy-structured with Pt/Pd atomic ratio up to 1:1 which were demonstrated by spectroscopic methods. We had also proved that the nanorods could function as peroxidase mimetic for the detection of H2O2, with the detection limit of 8.6 nM and the linear range from 20 nM to 50 mM. The result demonstrated that PtPd PNRs exhibited much higher affinity to H2O2 over other peroxidase mimetics due to synergistically integrating highly catalytic activity of two metals. On the basis of the peroxidase-like activity, the PtPd PNRs were used as a signal transducer to develop a novel and simple colorimetric method for the study of the flux of H2O2 released from living cell. By using 3,3,5,5-tetramethylbenzidine as substrate, the H2O2 concentration could be distinguished by naked-eye observation without any instrumentation or complicated design. The method developed a new platform for a reliable collection of information on cellular reactive oxygen species release. And the nanomaterial could be used as a power tool for a wide range of potential applications in biotechnology and medicine.

In this work, a microfluidic paper-based analytical device was further exploited by coupling with an electrophoretic separation technique for the first time. A low-cost, simple, portable, and disposable microfluidic paper-based electrophoretic device with an on-column wireless electro-generated chemiluminescence detector was demonstrated.

A facile and sensitive electrochemiluminescence (ECL) immunosensor for the detection of human carcinoembryonic antigen (CEA) was designed. The immunosensor used Pt nanoparticles dotted graphene–carbon nanotubes composites (Pt/Gr–CNTs) as a platform and carbon dots functionalized Pt/Fe nanoparticles (Pt/Fe@CDs) as bionanolabels. The Pt/Gr–CNTs was first synthesized using a facile ultrasonic method to modify the working electrode, which increases the surface area to capture a large amount of primary anti-CEA antibodies as well as improving the electronic transmission rate. The bionanolabels Pt/Fe@CDs prepared through ethanediamine linking, showed good ECL signal amplification performance. The reason is that the Pt/Fe@CDs nanocomposites as signal tags can increase CDs loading per immunoreaction in comparison with single CDs. The approach provided a good linear response range from 0.003 to 600 ng mL−1 with a low detection limit of 0.8 pg mL−1. The immunosensor showed good specificity, acceptable stability and reproducibility. Satisfactory results were obtained in the determination of CEA in human serum albumin samples. Hence, the proposed ECL immunosensor could become a promising method for tumor marker detection.

•A PEC sensor was established on a paper-based device which based on low-cost screen-printed paper-electrodes. The paper-based sensor was developed for highly sensitive PCP assay.•The AuNPs decorated paper working electrode (Au-PWE) was made through AuNPs layer growth on the surface of cellulose.•The polypyrrole-functionalized ZnO nanoparticles were attached to the electrode surface.•The sensor was connected μ-PAD and the molecular imprinting technique, could be successfully applied to the detection of PCP.Combining microfluidic paper-based analytical device (μ-PAD) and the molecular imprinting technique, a visible light photoelectrochemical (PEC) sensing platform for the detection of pentachlorophenol (PCP) was established on gold nanoparticles (AuNPs) decorated paper working electrode using polypyrrole-functionalized ZnO nanoparticles. Ascorbic acid (AA) was exploited as an efficient and nontoxic electron donor for scavenging photogenerated holes under mild solution medium and facilitating the generation of stable photocurrent. The microfluidic molecular imprinted polymer-based PEC analytical origami device is developed for the detection of PCP in the linear range from 0.01 ng mL−1 to 100 ng mL−1 with a low detection limit of 4 pg mL−1. This disposable microfluidic PEC origami device would provide a new platform for sensitive, specific, and multiplex assay in public health, environmental monitoring, and the developing world.

In this work, microfluidic paper-based analytical device (μ-PAD) was applied in a photoelectrochemical (PEC) method and thus a truly low-cost, simple, portable, and disposable microfluidic PEC origami device (μ-PECOD) was demonstrated. The molecular imprinting technique was introduced into microfluidic paper-based analytical devices (μ-PADs) through electropolymerization of molecular imprinted polyaniline (MPANI) in a novel Au nanoparticle (AuNP)-modified paper working electrode (Au-PWE). This is fabricated through the growth of an AuNP layer on the surfaces of cellulose fibers in the PWE. Under visible light irradiation, MPANI can generate the photoelectric transition from the highest occupied molecular orbital (HOMO) to the lowest unoccupied molecular orbital (LUMO), delivering the excited electrons to the AuNPs, and then to the carbon working electrode. Simultaneously, it is believed that a positively charged hole of MPANI that took part in the oxidation process was consumed by ascorbic acid (AA) to promote the amplifying photocurrent response. On the basis of this novel MPANI-Au-PWE and the principle of origami, a microfluidic molecular imprinted polymer (MIP)-based photoelectrochemical analytical origami device (μ-MPECOD), comprised of an auxiliary tab and a sample tab, is developed for the detection of heptachlor in the linear range from 0.03 nmol L−1 to 10.0 nmol L−1 with a low detection limit of 8.0 pmol L−1. The selectivity, reproducibility, and stability of this μ-MPECOD are investigated. This μ-MPECOD would provide a new platform for high-throughput, sensitive, specific, and multiplex assay in public health, environmental monitoring, and the developing world.

In this paper, a carbon coated magnetic nanoparticle (Fe3O4–C) was first synthesized via solvothermal reaction and carbonization of glucose under hydrothermal condition. The electrochemiluminescence (ECL) property of Fe3O4–C was studied, and exhibited a peak at 1.21 V. In the goal to amplify the ECL intensity for sensitive detection, a novel coaxial carbon coated magnetic nanomaterial (MWNTs–Fe3O4–C) was synthesized. Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), powder X-ray diffraction (XRD) and powder X-ray photoelectron spectrometry (XPS) were applied as powerful tools to characterize and to demonstrate the named nanomaterial. MWNTs–Fe3O4–C showed better ECL property than Fe3O4–C. Furthermore, an ultrasensitive ECL immunosensor based on MWNTs–Fe3O4–C was developed for the determination of carcinoembryonic antigen (CEA). The prepared ECL immunosensor exhibited high sensitivity, good reproducibility, long-term stability, and acceptable precision on the detection of CEA in clinical human serum samples.Highlights► The ECL property of amorphous carbon was proposed here. ► A novel “sugarcoated haws on a stick”-like MWNTs–Fe3O4–C was synthesized. ► The prepared MWNTs–Fe3O4–C was applied as a signal probe in an ECL immunosensor. ► AuNPs–EGN was employed as an immunosensing platform for target capture.

In this paper, a novel phenyleneethynylene derivative 4,4′-(2,5-dimethoxy-1,4-phenylene)bis(ethyne-2,1-diyl) dibenzoic acid (p-acid) was synthesized. Infrared spectroscopy (IR), nuclear magnetic resonance (NMR), photoluminescence (PL) spectroscopy and ultraviolet visible (UV-vis) spectroscopy were applied to characterize p-acid. The p-acid doped silica nanoparticle (p-acid@SiO2) was assembled in layer-by-layer (LBL) self-assembling processes using tetraethoxysilane (TEOS). Scanning electron microscope (SEM) and transmission electron microscope (TEM) were applied to characterize p-acid@SiO2. To research the practical applicability, a sample DNA sensor was constructed using p-acid@SiO2 label, in which the PL intensity response was proportion to the target-DNA (S2) concentration in the range of 0.05–1000 fM, with a detection limit of 20 pM. Furthermore, the DNA sensor showed high specificity, excellent stability, and good reproducibility. The p-acid@SiO2-based DNA sensor can also provide potential application for detection of other pathogen DNA.

In this paper, a novel phenyleneethynylene derivative 4,4′-(2,5-dimethoxy-1,4-phenylene)bis(ethyne-2,1-diyl) dibenzoic acid (p-acid) was synthesized. Infrared spectroscopy (IR), nuclear magnetic resonance (NMR), photoluminescence (PL) spectroscopy and ultraviolet visible (UV-vis) spectroscopy were applied to characterize p-acid. The p-acid doped silica nanoparticle (p-acid@SiO2) was assembled in layer-by-layer (LBL) self-assembling processes using tetraethoxysilane (TEOS). Scanning electron microscope (SEM) and transmission electron microscope (TEM) were applied to characterize p-acid@SiO2. To research the practical applicability, a sample DNA sensor was constructed using p-acid@SiO2 label, in which the PL intensity response was proportion to the target-DNA (S2) concentration in the range of 0.05–1000 fM, with a detection limit of 20 pM. Furthermore, the DNA sensor showed high specificity, excellent stability, and good reproducibility. The p-acid@SiO2-based DNA sensor can also provide potential application for detection of other pathogen DNA.

In this work, a microfluidic paper-based analytical device was further exploited by coupling with an electrophoretic separation technique for the first time. A low-cost, simple, portable, and disposable microfluidic paper-based electrophoretic device with an on-column wireless electro-generated chemiluminescence detector was demonstrated.