Automated Support-Resolution Strategy for a One-Way Chemiluminescent Multiplex Immunoassay

Anthracycline-Functionalized Dextran as a New Signal Multiplication Tagging Approach for Immunoassay

The most used kind of immunoassay is enzyme-linked immunosorbent assay (ELISA); however, enzymes suffer from steric effects, low stability, and high cost. Our research group has been developing quinone-linked immunosorbent assay (QuLISA) as a new promising approach for stable and cost-efficient immunoassay. However, the developed QuLISA suffered from low water-solubility of synthesized quinone labels and their moderate sensitivity. Herein, we developed a new approach for signal multiplication of QuLISA utilizing the water-soluble quinone anthracycline, doxorubicin, coupled with dextran for signal multiplication. A new compound, Biotin-DexDox, was prepared in which doxorubicin was assembled on oxidized dextran 40, and then it was biotinylated. The redox-cycle-based chemiluminescence and the colorimetric reaction of Biotin-DexDox were optimized and evaluated, and they showed very good sensitivity down to 0.25 and 0.23 nM, respectively. Then, Biotin-DexDox was employed for the detection of biotinylated antibodies utilizing avidin as a binder and a colorimetric assay of the formed complex through its contained doxorubicin redox reaction with NaBH₄ and imidazolium salt yielding strong absorbance at 510 nm. The method could detect the plate-fixed antibody down to 0.55 nM. Hence, the application of Biotin-DexDox in QuLISA was successfully demonstrated and showed a significant improvement in its sensitivity and applicability to aqueous assays.

A DNA dendrimer amplified electrochemical immunosensing method for highly sensitive detection of prostate specific antigen

This work designed a DNA dendrimer for the loading of signal molecule and the construction of amplified electrochemical immunosensing method. The DNA dendrimer was self-assembled by the hybridization of one couple of complementary oligonucleotides (DNA and cDNA) that were covalently conjugated to three arms of a Y-shaped cross-linker, tris(2-maleimidoethyl)amine (TMEA) respectively. The immunosensor was prepared by coating chitosan on glassy carbon electrode to covalently immobilize the capture antibody with glutaraldehyde as a linker. After the target protein was captured on the immunosensor, cDNA-labeled secondary antibody was bound on the surface via a sandwiched immunoreaction to introduce the DNA dendrimer onto immunosensor for loading abundant methylene blue as signal molecule, which amplified greatly the amperometric signal for immunoassay. Using prostate specific antigen (PSA) as a model analyte, this proposed method showed a wide linear range from 1 pg mL^-1 to 10 ng mL^-1 along with a limit of detection down to 0.26 pg mL^-1. The designed strategy avoided complex synthesis of signal tags, and possessed excellent performance for analysis of practical samples, thus providing a new avenue for the development of signal amplification strategy and immunoassay methods.

A multimer-based SERS aptasensor for highly sensitive and homogeneous assay of carcinoembryonic antigens

Carcinoembryonic antigens (CEAs) are known as one of the most common tumor markers. Their facile and affordable detection is critical for early diagnosis of malignant tumors, especially in resource-constrained settings. Here, we report a novel multimer-based surface-enhanced Raman scattering (SERS) aptasensor for a specific CEA assay. The aptasensor is fabricated through aptamer-assisted self-assembly of silver-coated gold nanoparticles (Au@Ag NPs), and the self-assembled multimeric structure possesses abundant hot-spots to provide high SERS response. When CEA is introduced, the specific recognition of CEA by aptamers will lead to the disassembly of Au@Ag multimers due to the lack of a bridging aptamer between Au@Ag NPs. As a result, the number of hot-spots in the multimeric system is decreased, and the intensity at 1585 cm-1 of the SERS reporter (4-mercaptobenzoic acid, 4-MBA) on the surface of NPs will also be decreased. The Raman intensity is proportional to the logarithm of the concentration of CEA. The detection sensitivity can be down to the pg mL-1 level. The analytical method only needs a droplet of 2 μL of sample, and the detection time is less than 20 min. The multimer-based SERS aptasensor can be applied in sensitive and inexpensive detection of CEA in serum samples.

A new method to amplify colorimetric signals of paper-based nanobiosensors for simple and sensitive pancreatic cancer biomarker detection

A low-cost, sensitive, and disposable paper-based immunosensor for instrument-free colorimetric detection of pancreatic cancer biomarker PEAK1 was reported for the first time by capitalizing the catalytic properties of gold nanoparticles in colour dye degradation. This simple signal amplification method enhances the detection sensitivity by about 10 fold.

Simultaneous quantitative detection of multiple tumor markers in microfluidic nanoliter-volume droplets

We developed a simultaneous detection method for multiple tumor markers (TMs) in microfluidic droplets based on a multiple fluorescence resonance energy transfer (FRET) system. In this system, graphene oxide (GO) was used as the single quencher, while the multi-color quantum dots (QDs) labeled on different aptamers were employed as energy donors. When the aptamers were adsorbed onto GO due to the π-π stacking interaction, QDs were drawn to the surface of GO and quenched by it. Once the TMs were introduced, the corresponding fluorescence of QDs was recovered obviously owing to the preferential interaction of aptamers with the TMs. Here, the multi-FRET system was encapsulated into nanoliter-volume droplets by a simple T-junction microfluidic chip. The targets could be detected rapidly as the generated droplets flew through the integrated on-line detection zone. Three tumor markers, carcinoembryonic antigen (CEA), prostate-specific antigen (PSA) and vascular endothelial growth factor (VEGF₁₆₅) could be detected simultaneously in 33 nL-volume droplets, which is only 1/3000 of the volume of the sample consumed in the conventional fluorescence spectrophotometer. In addition, the signals corresponding to different TM targets in one nanoliter-volume droplet could be read out at the same time, and the signals could be output continuously owing to the uninterruptible generation of droplets. Even with a signal acquisition frequency of 55 droplets per minute, the multi-FRET biosensing system has linear ranges of 0.50-70 ng mL^-1 for CEA, 0.25-70 ng mL^-1 for PSA and 0.50-70 ng mL^-1 for VEGF₁₆₅. The detection limits of CEA, PSA and VEGF₁₆₅ were calculated to be 0.15 ng mL^-1, 0.035 ng mL^-1 and 0.11 ng mL^-1, respectively. The method was also validated by analyzing human serum sample dilutions. The proposed multi-FRET-based system has potential to become a powerful tool for rapid, low-cost and simultaneous detection of multiple tumor markers.

A graphene oxide-based label-free electrochemical aptasensor for the detection of alpha-fetoprotein

A label-free method for the determination of alpha-fetoprotein (AFP) was successfully developed by graphene oxide (GO)-based electrochemical aptasensor. This aptasensor was constructed by covalently immobilizing NH₂-functionalized AFP-specific aptamer on GO with plenty of carboxylic groups. Cyclic voltammetry (CV) and electrochemical impedance spectra (EIS) analysis were carried out to investigate the practicability of the fabrication procedures. Fourier transform infrared spectra (FTIR), Raman, atomic force microscopy (AFM) and scanning electron microscope (SEM) were performed to indicate the changes of the sensing interface. CV was used to detect the signal change of the aptasensor. Peak current of CVs changed before and after incubating the aptasensor with different concentration of AFP solution. The changes of peak current were proportional to the AFP concentration, with a wide linear range of 0.01-100 ng mL^-1, a low detection limit of 3 pg mL^-1 and good specificity. The proposed simple and cost-effective label-free strategy is promising for the determination of clinical biomarkers such as AFP.

A single-interface photoelectrochemical sensor based on branched TiO2 nanorods@strontium titanate for the detection of two biomarkers

Based on the enhanced photogenerated charge-separation properties of B-TiO₂ NRs@SrTiO₃ heterostructures, a photoelectrochemical sensor for detecting alpha fetoprotein and cancer antigen 153 at a single interface was first established.

Efficient label-free chemiluminescent immunosensor based on dual functional cupric oxide nanorods as peroxidase mimics

Dual-functional cupric oxide nanorods (CuONRs) as peroxidase mimics are proposed for the development of a flow-through, label-free chemiluminescent (CL) immunosensor. Forming the basis of this cost-efficient, label-free immunoassay, CuONRs, synthesized using a simple hydrothermal method, were deposited onto epoxy-activated standard glass slides, followed by immobilization of biotinylated capture antibodies through a streptavidin bridge. The CuONRs possess excellent catalytic activity, along with high stability as a solid support. Antigens could then be introduced to the sensing system, forming large immunocomplexes that prevent CL substrate access to the surface, thereby reducing the CL signal in a concentration dependent fashion. Using carcinoembryonic antigen (CEA) as a model analyte, the proposed label-free immunosensor was able to rapidly determine CEA with a wide linear range of 0.1-60ngmL^-1 and a low detection limit of 0.05ngmL^-1. This nanozyme-based immunosensor is simple, sensitive, cost-efficient, and has the potential to be a very promising platform for fast and efficient biosensing applications.

A non-enzyme cascade amplification strategy for colorimetric assay of disease biomarkers

A non-enzyme cascade amplification strategy for colorimetric assay of disease biomarkers with substantially enhanced detection sensitivity has been developed.

All-in-one dual-aptasensor capable of rapidly quantifying carcinoembryonic antigen

Using a dual DNA aptamer (CEA aptamer linked to hemin aptamer), capable of rapidly capturing carcinoembryonic antigen (CEA) and hemin, an all-in-one dual-aptasensor with 1,1'-oxalyldiimidazole (ODI) chemiluminescence detection was developed for the early diagnosis of human cancer. CEA and hemin competitively bound with the dual DNA aptamer while the mixture in a detection cell was incubated for 30min at room temperature. When Amplex Red and H₂O₂ were added in the detection cell after the incubation, the yield of resorufin formed from the reaction Amplex Red and H₂O₂ depended on the concentration of HRP-mimicking G-quardruplex DNAzyme formed from the binding interaction between hemin and the dual DNA aptamer. Bright red light was observed with the addition of ODI and H₂O₂ in the detection cell containing resorufin. Relative CL intensity of all-in-one dual-aptasensor, operated with the competitive reaction of CEA and hemin in the presence of the dual aptamer, was exponentially decreased with the increase of CEA concentration in human serum. The limit of detection (LOD=3σ) of the all-in-one dual-aptasensor which operated with excellent accuracy, precision, and reproducibility was as low as 0.58ng/ml. The good correlation between the easy to use all-in-one dual-aptasensor and conventional enzyme-linked immunosorbent assay (ELISA), operated with time consuming procedures (e.g., long incubations and multiple washings), indicates that the rapid all-in-one dual-aptasensor can be applied as a novel clinical tool for the early diagnosis of breast cancer.

A Highly Selective and Sensitive Fluorescence Detection Method of Glyphosate Based on an Immune Reaction Strategy of Carbon Dot Labeled Antibody and Antigen Magnetic Beads

A sensitive fluorescence detection method for glyphosate (GLY) was established based on immune reaction. First, carbon dot labeled antibodies (lgG-CDs) which were able to specifically identify glyphosate were prepared with the environmentally friendly carbon dots (CDs) and glyphosate antibody (lgG). lgG-CDs could be used to in situ visualize the distribution of glyphosate in plant tissues. In order to eliminate the effects of excess lgG-CDs on the determination of GLY, antigen magnetic beads Fe3O4-GLY based on magnetic nanoparticles Fe3O4 and glyphosate were constructed and utilized to couple with the excess lgG-CDs. After magnetic separation to remove antigen magnetic beads, there was a linear relationship between the fluorescence intensity of lgG-CDs and the logarithmic concentration of glyphosate in the range of 0.01-80 μg/mL with a detection limit of 8 ng/mL. The method was used for the detection of glyphosate in Pearl River water, tea, and soil samples with satisfactory recovery ratio between 87.4% and 103.7%.

Smart CuS Nanoparticles as Peroxidase Mimetics for the Design of Novel Label-Free Chemiluminescent Immunoassay

In the present work, a novel label-free chemiluminescent (CL) immunoassay method was designed by employing smart CuS nanoparticles (CuSNPs) as peroxidase mimetics. The CuSNPs were synthesized through a simple coprecipitation method, and showed high catalytic activity and stability. This efficient label-free CL immunoassay could be easily achieved through a simple strategy. First, CuSNPs dispersed in chitosan were modified on the epoxy-functionalized glass slide to form a solid CL signal interface. Streptavidin was then used to functionalize CuSNPs to capture the biotinylated antibody, further producing a sensing interface. After online incubation with antigen molecules, the formed antibody-antigen complex on the biosensing substrate could prevent the diffusion channel of CL substrate toward the signal interface, and restrained the mimic enzyme-catalyzed CL reaction, finally resulting in the decrease of CL signals of the assay system. Compared to the label-based CL immunoassay, the proposed label-free assay mode is more simple, cheap and fast. Using a model analyte alpha-fetoprotein, the label-free CL immunoassay method had a linear range of 0.1-60 ng/mL and a low detection limit of 0.07 ng/mL. Moreover, the peroxidase mimetic-based label-free CL immunoassay system showed good specificity, acceptable repeatability, and good accuracy. The study provided a promising strategy for the development of highly efficient label-free CL immunoassay system.

Using carbon nanotubes-gold nanocomposites to quench energy from pinnate titanium dioxide nanorods array for signal-on photoelectrochemical aptasensing

On the basis of the absorption and emission spectra overlap, an enhanced resonance energy transfer caused by excition-plasmon resonance between carbon nanotubes-gold nanoparticles (CNTs-Au) and pinnate titanium dioxide nanorods array (P-TiO2 NA) was obtained. Three-dimensional single crystalline P-TiO2 were prepared successfully on fluorine-doped tin oxide conducting glass (FTO glass), and its optical absorption properties and photoelectrochemical (PEC) properties were investigated. With the synergy of CNTs-Au as energy acceptor, it resulted in the enhancement of energy transfer between excited P-TiO2 NA and CNTs-Au. Upon the novel sandwichlike structure formed via DNA hybridization, the exciton produced in P-TiO2 NA was annihilated and a damped photocurrent was obtained. With the use of carcinoembryonic antigen (CEA) as a model which bonded to its specific aptamer and destroyed the sandwichlike structure, the energy transfer efficiency was lowered, leading to PEC response augment. Thus a signal-on PEC aptasensor was constructed. Under the optimal conditions, the PEC aptasensor for CEA determination exhibited a linear range from 0.001 to 2.5ngmL(-1) with a detection limit of 0.39pgmL(-1) and was satisfactory for clinical sample detection. Furthermore, the proposed aptasensor shows satisfying performance, such as easy preparation, rapid detection and so on. Moreover, since different aptamer can specifically bind to different target molecules, the designed strategy has an expansive application for the construction of versatile PEC platforms.

Opto-Microfluidic Immunosensors: From Colorimetric to Plasmonic

Optical detection has long been the most popular technique in immunosensing. Recent developments in the synthesis of luminescent probes and the fabrication of novel nanostructures enable more sensitive and efficient optical detection, which can be miniaturized and integrated with microfluidics to realize compact lab-on-a-chip immunosensors. These immunosensors are portable, economical and automated, but their sensitivity is not compromised. This review focuses on the incorporation and implementation of optical detection and microfluidics in immunosensors; it introduces the working principles of each optical detection technique and how it can be exploited in immunosensing. The recent progress in various opto-microfluidic immunosensor designs is described. Instead of being comprehensive to include all opto-microfluidic platforms, the report centers on the designs that are promising for point-of-care immunosensing diagnostics, in which ease of use, stability and cost-effective fabrication are emphasized.

An enhanced photoelectrochemical platform: graphite-like carbon nitride nanosheet-functionalized ZnO nanotubes

Large-scale two-dimensional graphite-like carbon nitride nanosheets with obvious upconversion properties were prepared by a liquid exfoliation route and used to functionalize ZnO nanotubes to construct a photoelectrochemical platform.

Enhanced photoelectrochemical aptasensing platform amplified through the sensitization effect of CdTe@CdS core–shell quantum dots coupled with exonuclease-I assisted target recycling

The sensitization of CdTe@CdS core–shell quantum dots on N-doped mesoporous TiO₂, integrated with exonuclease-I assisted target recycling, was applied to construct an enhanced photoelectrochemical aptasensing platform.

Dual-primer self-generation SERS signal amplification assay for PDGF-BB using label-free aptamer

Highly sensitive detection of proteins, especially those associated with cancers, is essential to biomedical research as well as clinical diagnosis. In this work, a simple and novel one-two-three signal amplification surface-enhanced Raman scattering (SERS) method for the detection of protein is fabricated by using label-free aptamer and dual-primer self-generation. Platelet-derived growth factor B-chain (PDGF-BB) is selected as the model protein. The one-two-three cascade DNA amplification means one target-aptamer binding event, two hairpin DNA switches and three DNA amplification reactions. This strategy possesses some remarkable features compared to conventional signal amplification methods: (i) A smart probe including a label-free aptamer is fabricated, for suitable hybridization without hindering the affinity of the aptamer toward its target. (ii) Using the unique structure switch of the aptamer and cooperator, a one-two-three working mode is developed to amplify the SERS signal. The amplification efficiency is enhanced. Given the unique and attractive characteristics, a simple and universal strategy is designed to accomplish ultrasensitive detection of proteins. The detection limit of PDGF-BB via SERS detection is 0.42 pM, with the linear range from 1.0×10(-12)M to 10(-8)M. It is potentially universal because the aptamer can be easily designed for biomolecules whose aptamers undergo similar conformational changes.

A new label-free strategy for a highly efficient chemiluminescence immunoassay

A new label-free chemiluminescence (CL) immunoassay method which is based on the co-immobilization of a capture antibody and horseradish peroxidase (HRP) on the Au nanoparticle–chitosan composite interface is proposed for the cheap, fast and convenient detection of proteins.

Multiplexed detection of two proteins by a reaction kinetics-resolved chemiluminescence immunoassay strategy

A multiplexed immunoassay method was proposed for the sequential detection of two proteins based on a novel chemiluminescence reaction kinetics-resolved strategy.

Label-free and highly sensitive electrochemiluminescence biosensing using quantum dots/carbon nanotubes in ionic liquid

A universal and label-free electrochemiluminescence biosensing platform with high sensitivity was developed based on quantum dots/carbon nanotubes in ionic liquid.

Photoelectrochemical biosensor using enzyme-catalyzed in situ propagation of CdS quantum dots on graphene oxide

An innovative photoelectrochemical (PEC) biosensor platform was designed based on the in situ generation of CdS quantum dots (QDs) on graphene oxide (GO) using an enzymatic reaction. Horseradish peroxidase catalyzed the reduction of sodium thiosulfate with hydrogen peroxide to generate H2S, which reacted with Cd(2+) to form CdS QDs. CdS QDs could be photoexcited to generate an elevated photocurrent as a readout signal. This strategy offered a "green" alternative to inconvenient presynthesis procedures for the fabrication of semiconducting nanoparticles. The nanomaterials and assembly procedures were characterized by microscopy and spectroscopy techniques. Combined with immune recognition and on the basis of the PEC activity of CdS QDs on GO, the strategy was successfully applied to a PEC assay to detect carcinoembryonic antigen and displayed a wide linear range from 2.5 ng mL(-1) to 50 μg mL(-1) and a detection limit of 0.72 ng mL(-1) at a signal-to-noise ratio of 3. The PEC biosensor showed satisfactory performance for clinical sample detection and was convenient for determining high concentrations of solute without dilution. This effort offers a new opportunity for the development of numerous rapid and convenient analytical techniques using the PEC method that may be applied in the design and preparation of various solar-energy-driven applications.

Using ruthenium polypyridyl functionalized ZnO mesocrystals and gold nanoparticle dotted graphene composite for biological recognition and electrochemiluminescence biosensing

Using ruthenium polypyridyl functionalized ZnO mesocrystals as bionanolabels, a universal biological recognition and biosensing platform based on gold nanoparticle (AuNP) dotted reduced graphene oxide (rGO) composite was developed. AuNP-rGO accelerated electron transfer between the detection probe and the electrode, and increased the surface area of the working electrode to load greater amounts of the capture antibodies. The large surface area of ZnO mesocrystals was beneficial for loading a high content ruthenium polypyridyl complex, leading to an enhanced electrochemiluminescence signal. Using α-fetoprotein (AFP) as a model, a simple and sensitive sandwich-type electrochemiluminescence biosensor with tripropylamine (TPrA) as a coreactant for detection of AFP was constructed. The designed biosensor provided a good linear range from 0.04 to 500 ng mL(-1) with a low detection limit of 0.031 ng mL(-1) at a S/N of 3 for AFP determination. The proposed biological recognition and biosensing platform extended the application of ruthenium polypyridyl functionalized ZnO mesocrystals, which provided a new promising prospect.

Using graphene-based plasmonic nanocomposites to quench energy from quantum dots for signal-on photoelectrochemical aptasensing

On the basis of the absorption and emission spectra overlap, an enhanced resonance energy transfer caused by excition-plasmon resonance between reduced graphene oxide (RGO)-Au nanoparticles (AuNPs) and CdTe quantum dots (QDs) was obtained. With the synergy of AuNPs and RGO as a planelike energy acceptor, it resulted in the enhancement of energy transfer between excited CdTe QDs and RGO-AuNPs nanocomposites. Upon the novel sandwichlike structure formed via DNA hybridization, the exciton produced in CdTe QDs was annihilated. A damped photocurrent was obtained, which was acted as the background signal for the development of a universal photoelectrochemical (PEC) platform. With the use of carcinoembryonic antigen (CEA) as a model which bonded to its specific aptamer and destroyed the sandwichlike structure, the energy transfer efficiency was lowered, leading to PEC response augment. Thus a signal-on PEC aptasensor was constructed. Under 470 nm irradiation at -0.05 V, the PEC aptasensor for CEA determination exhibited a linear range from 0.001 to 2.0 ng mL(-1) with a detection limit of 0.47 pg mL(-1) at a signal-to-noise ratio of 3 and was satisfactory for clinical sample detection. Since different aptamers can specifically bind to different target molecules, the designed strategy has an expansive application for the construction of versatile PEC platforms.

Ultrasensitive electrochemical immunosensors for multiplexed determination using mesoporous platinum nanoparticles as nonenzymatic labels

An ultrasensitive multiplexed immunoassay method was developed at a disposable immunosensor array using mesoporous platinum nanoparticles (M-Pt NPs) as nonenzymatic labels. M-Pt NPs were prepared by ultrasonic method and employed to label the secondary antibody (Ab2) for signal amplification. The immunosensor array was constructed by covalently immobilizing capture antibody (Ab1) on graphene modified screen printed carbon electrodes (SPECs). After the sandwich-type immunoreactions, the M-Pt-Ab2 was bound to immunosensor surface to catalyze the electro-reduction of H2O2 reaction, which produced detectable signals for readout of analytes. Using breast cancer related panel of tumor markers (CA125, CA153 and CEA) as model analytes, this method showed wide linear ranges of over 4 orders of magnitude with the detection limits of 0.002 U mL(-1), 0.001 U mL(-1) and 7.0 pg mL(-1) for CA125, CA153 and CEA, respectively. The disposable immunosensor array possessed excellent clinical value in cancer screening as well as convenient point of care diagnostics.

Recent developments in emerging microimmunoassays

Creative and novel microimmunoassay approaches continue to proliferate across many platforms originating from several fields of study. These efforts are aimed at improving one or more metrics for clinical tests, including improved sensitivity, increased speed, reduced cost, smaller sample size, the ability to analyze multiple antigens in parallel and ease of use. Many approaches focus on the production of microarrays that accomplish standard assays in parallel, or mobile solid-support formats to overcome issues of high background noise and long incubation times. In this article, innovative developments beyond existing commercial tests in the microimmunoassay arena are reviewed, covering January 2008 to April 2012. These developing experimental platforms are discussed in terms of their ability to augment or replace current commercial approaches.

Microfluidic chips for immunoassays

The use of microfluidic chips for immunoassays has been extensively explored in recent years. The combination of immunoassays and microfluidics affords a promising platform for multiple, sensitive, and automatic point-of-care (POC) diagnostics. In this review, we focus on the description of recent achievements in microfluidic chips for immunoassays categorized by their detection method. Following a brief introduction to the basic principles of each detection method, we examine current microfluidic immunosensor detection systems in detail. We also highlight interesting strategies for sensitive immunosensing configurations, multiplexed analysis, and POC diagnostics in microfluidic immunosensors.

Battery-triggered microfluidic paper-based multiplex electrochemiluminescence immunodevice based on potential-resolution strategy

A potential-resolution strategy for multiplex electrochemiluminescence (ECL) immunoassay on a microfluidic paper-based analytical device (μ-PAD) was demonstrated for the first time, using tris-(bipyridine)-ruthenium(ii) (Ru(bpy)(3)(2+)) and carbon nanodots (CNDs) as the ECL labels for high-throughput ECL immunoassay on μ-PAD. Based on this strategy, simultaneous detection of four tumor markers using only two screen-printed carbon working electrodes (one electrode for two analytes) on an immunodevice consisting of a piece of patterned paper (denoted as μ-PECLI in this work) was realized, which is a simplification of the configuration of traditional μ-PADs. As a further development of μ-PECLI in low-cost and disposable applications, battery-triggered (constant-potential) ECL detection on μ-PECLI was developed, allowing the traditional electrochemical workstation to be abandoned. In addition, to exactly control the output voltage of the battery, a low-cost and simple voltage-controller was designed and fabricated for the first time. The battery-triggered ECL immunoassay principle on μ-PECLI is explained. We found that the simultaneous determination of two analytes in one paper working zone could be achieved by controlling the operational constant-potential (+1.2 V for Ru(bpy)(3)(2+) labels and -1.2 V for CNDs labels (vs. Ag/AgCl auxiliary electrode)) by simply reversing the connection mode. Finally, four tumor markers in human serum samples from the Tumor Hospital were assayed and the results obtained were in acceptable agreement with the reference values from parallel single-analyte test. This battery-triggered μ-PECLI provides a new strategy for high-throughput, low-cost, sensitive, automated and simultaneous multiplex immunoassay and point-of-care diagnosis.