Dual-responsive 3D DNA nanomachines cascaded hybridization chain reactions for novel self-powered flexible microRNA-detecting platform.

The microRNA-21 is closely related to chromatin remodeling and epigenetic regulation. In this work, an efficient double-response 3D DNA nanomachine (DRDN) was assembled by co-immobilizing two different lengths of hairpin DNA on the surface of gold nanoparticles (AuNPs) to capture microRNA-21 (miRNA-21), recycle miRNA-21, and trigger hybridization chain reactions (HCR). This work reports the fabrication of a laser-scribed graphene (LSG) electrode with excellent flexibility and electrical conductivity by laser-scribing commercial polyimide films (PI). The as-proposed self-powered biosensing platform presents significantly increased instantaneous current to in real-time monitor miRNA-21 by a capacitor. The biosensing platform exhibited highly sensitive detection of miRNA-21 with a detection limit of 0.142 fM in the range of 0.5 fM to 1 × 104 fM, and demonstrated high efficiency in the analysis of the tumor markers.

Novel hollow MoS2@C@Cu2S heterostructures for high zinc storage performance.

Heterostructured materials have great potential as cathodes for zinc-ion batteries (ZIBs) because of their fast Zn2+ transport channels. Herein, hollow MoS2@C@Cu2S heterostructures are innovatively constructed using a template-engaged method. The carbon layer improves the electrical conductivity, provides a high in situ growth area, and effectively restricts volume expansion during the recycling process. MoS2 nanosheets are grown on the surfaces of hollow C@Cu2S nanocubes using the in situ template method, further expanding the specific surface area and exposing more active sites to enhance the electrical conductivity. As expected, an admirable reversible capacity of 197.2 mA h g-1 can be maintained after 1000 cycles with a coulombic efficiency of 91.1%. Therefore, we firmly believe that this work points the way forward for high-performance materials design and energy storage systems.

Self-Powered Biosensing System with Multivariate Signal Amplification for Real-Time Amplified Detection of PDGF-BB.

A self-powered biosensing system with multivariate signal amplification is designed for the ultrasensitive, highly efficient, rapid-response, and real-time detection of platelet-derived growth factor-BB (PDGF-BB). The biosensing system is composed of enzymatic biofuel cells (EBFCs), a capacitor, a digital multimeter (DMM), and a computer. Using the hybridization chain reaction (HCR), a few single DNA chains are transformed into abundant double-helix chains, which stimulates the reduction of [Ru(NH3)6]3+ to [Ru(NH3)6]2+ by electrostatic interaction, corresponding to the "on" state for HCR. As a result, the open-circuit voltage (EOCV) is significantly increased in this self-powered biosensing system. When PDGF-BB is present, a binding interaction between the target and the aptamer, i.e., PDGF-BB/Apt, corresponding to the "off" state for HCR, results in a decrease of EOCV. The PDGF-BB concentration is inversely proportional to EOCV, allowing readable, effective, and precise real-time detection of PDGF-BB. The detection limit of the biosensing system is 0.031 pg/mL (S/N = 3). This strategy provides a promising and powerful tool for the early clinical diagnosis of related colorectal cancer markers.

Novel Ultralow-Potential Electrochemiluminescence Aptasensor for the Highly Sensitive Detection of Zearalenone Using a Resonance Energy Transfer System.

An ultralow-potential electrochemiluminescence (ECL) aptasensor has been designed for zearalenone (ZEN) assay based on a resonance energy transfer (RET) system with SnS2 QDs/g-C3N4 as a novel luminophore and CuO/NH2-UiO-66 as a dual-quencher. SnS2 QDs were loaded onto g-C3N4 nanosheets and enhanced the ECL luminescence via strong synergistic effects under an ultralow potential. The UV-vis absorption spectrum of CuO/NH2-UiO-66 exhibits considerable overlap with the ECL emission spectrum of SnS2 QDs/g-C3N4, an important consideration for the RET process. In order to stimulate RET, the ZEN aptamer and complementary DNA are introduced for conjugation between the donor and the acceptor. With the binding interaction between ZEN by its aptamer, CuO/NH2-UiO-66 is removed from the electrode surface, resulting in the inhibition of the RET system and an increase in the ECL signal. Under optimal conditions, the as-prepared aptasensor quantified ZEN from 0.5 µg·mL-1 to 0.1 fg·mL-1 with a low limit of detection of 0.085 fg·mL-1, and it exhibited good stability, excellent specificity, high reproducibility, and desirable practicality. The sensing strategy provides a method for mycotoxins assay to monitor food safety.

Self-Powered Biosensor Based on DNA Walkers for Ultrasensitive MicroRNA Detection.

A novel self-powered biosensor is fabricated for ultrasensitive microRNA-21 (miRNA-21) detection, which includes an enzymatic biofuel cell (EBFC), DNA walkers, a digital multimeter (DMM), and a capacitor. As a novel strategy for signal amplification, DNA walkers are designed in the cathode, while the capacitor stores electrochemical energy from the EBFC to further boost the instantaneous current displayed by the DMM. When miRNA-21 is present, the DNA walkers are provoked to walk from as-opened hairpin structures to other hairpin structures, generating double-strand DNA structures, which stimulate [Ru(NH3)6]3+ to be adsorbed on the cathode surface by electrostatic interaction. Afterward, [Ru(NH3)6]3+ is reduced to [Ru(NH3)6]2+, and the open circuit voltage (EOCV) is significantly increased. Depending on the approach of signal amplification from DNA walkers, this biosensor displays an ultrasensitive assay toward miRNA-21 in the range of 0.5 to 104 fM, with a detection limit of 0.15 fM. In addition, this self-powered biosensor displays high selectivity for miRNA-21 assay in human serum samples.

GLP-1 plays a protective role in hippocampal neuronal cells by activating cAMP-CREB-BDNF signaling pathway against CORT+HG-induced toxicity.

Major depressive disorder (MDD) with diabetes mellitus (DM) significantly reduces the quality of the patient's life, and currently, there is no effective treatment. This study explored the feasibility of Glucagon-like peptide-1 (GLP-1) in treating MDD combined with DM. The protective effects of GLP-1 on mouse hippocampal neuronal cell line HT22 cultured with corticosterone (CORT) and high glucose (HG) were assessed. HT22 cells were cultured with CORT + HG to construct a cell model of MDD combined with DM. Cell viability and cell apoptosis/necrocytosis were detected by CCK-8 assay and flow cytometry/confocal laser scanning microscopy, respectively, after treatment with GLP-1. In addition, BDNF and neurotransmitter levels, lactic dehydrogenase (LDH) and glucose levels, and proteins of cAMP-CREB-BDNF signal pathway in the culture supernatants were measured through an enzyme-linked immunosorbent assay and colorimetric assays and Western blot, respectively. The ideal intervention combination to construct a cell model of MDD combined with DM was CORT 200 µM and HG 50 mM for 48 h. After treatment of 50 nM GLP-1 for 48 h, the model+50 nM GLP-1 group's apoptosis and necrocytosis rates and LDH and glucose concentrations in the culture supernatants decreased significantly compared with the model group. However, the BDNF, 5-hydroxytryptamine (5-HT), dopamine (DA), norepinephrine (NE), PKA, p-CREB, and p-Trkb concentrations in the culture supernatants increased significantly. GLP-1 functioned against CORT + HG-induced toxicity by activating the cAMP-CREB-BDNF signaling pathway in hippocampal neuronal cells.

Comprehensive transcriptomics and metabolomics analyses reveal that hyperhomocysteinemia is a high risk factor for coronary artery disease in a chinese obese population aged 40-65: a prospective cross-sectional study.

BACKGROUND: Clinical observations suggest a complex relationship between obesity and coronary artery disease (CAD). This study aimed to characterize the intermediate metabolism phenotypes among obese patients with CAD and without CAD. METHODS: Sixty-two participants who consecutively underwent coronary angiography were enrolled in the discovery cohort. Transcriptional and untargeted metabolomics analyses were carried out to screen for key molecular changes between obese patients with CAD (CAD obese), without CAD (Non-CAD obese), and Non-CAD leans. A targeted GC-MS metabolomics approach was used to further identify differentially expressed metabolites in the validation cohorts. Regression and receiver operator curve analysis were performed to validate the risk model. RESULTS: We found common aberrantly expressed pathways both at the transcriptional and metabolomics levels. These pathways included cysteine and methionine metabolism and arginine and proline metabolism. Untargeted metabolomics revealed that S-adenosylhomocysteine (SAH), 3-hydroxybenzoic acid, 2-hydroxyhippuric acid, nicotinuric acid, and 2-arachidonoyl glycerol were significantly elevated in the CAD obese group compared to the other two groups. In the validation study, targeted cysteine and methionine metabolomics analyses showed that homocysteine (Hcy), SAH, and choline were significantly increased in the CAD obese group compared with the Non-CAD obese group, while betaine, 5-methylpropanedioic acid, S-adenosylmethionine, 4-PA, and vitamin B2 (VB2) showed no significant differences. Multivariate analyses showed that Hcy was an independent predictor of obesity with CAD (hazard ratio 1.7; 95%CI 1.2-2.6). The area under the curve based on the Hcy metabolomic (HCY-Mtb) index was 0.819, and up to 0.877 for the HCY-Mtb.index plus clinical variables. CONCLUSION: This is the first study to propose that obesity with hyperhomocysteinemia is a useful intermediate metabolism phenotype that could be used to identify obese patients at high risk for developing CAD.

Proteins and signaling pathways response to Wenjingtongluo drug-contained serum in IHUVECs: an explorative proteomic study.

Angiogenesis is a dynamic and complex process leading to the development of new vessels from pre-existing vessels, which played a major role in pathological processes in many diseases. The present study aimed to investigate the effect of drug-contained serum of Traditional Chinese medicine (TCM) Wenjingtongluo decoction (WJLTD) on antiangiogenesis in Immortalized Human Umbilical Vascular Endothelial cells (IHUVECs), and elucidate the possible mechanisms based on proteomic analysis. Cells were treated with the drug-contained serum of the Drug-contained Serum (DS) of WJLTD and the blank serum (BS). The antiangiogenesis capacity of DS was evaluated using wound healing assay, Transwell, and tube formation assay. We performed three biological replicates to compare large-scale differential protein expression between two groups by tandem mass tag (TMT) labeling technology based on liquid chromatography-mass spectrometry analysis (LC-MS/MS). Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed for the general characterization of overall enriched proteins. For validation of the results of TMT, the candidate proteins were verified by parallel reaction monitoring (PRM) analysis. The results showed that 4% DS could inhibit the migration process of IHUVECs according to wound healing assay and Transwell. And tube formation ability was also dramatically inhibited (p<0.001). TMT analysis revealed 148 differentially expressed proteins between two groups that were identified and quantified. The further validation results of the two candidate proteins, Ferritin heavy chain (FTH1) and Ferritin light chain (FTL) from the Ferroptosis pathway, which played an important role in DS treatment, were consistent with those of LC-MS/MS. In conclusion, this is the first proteomics-based study to report the mechanism underlying DS treatment for angiogenesis. Further functional verification of the potential signaling pathways and the enriched proteins is warranted.

AuPt Nanodonuts as a Novel Coreaction Accelerator and Luminophore for a Label-free Electrochemiluminescence Aptasensor.

Novel and effective coreaction accelerators are of great importance in electrochemiluminescence (ECL) systems. In this work, novel AuPt nanodonuts, i.e., SnS2 quantum dots (QDs)/Cys-AuPt heterogeneous nanorings (NRs), serve as both a highly effective coreaction accelerator and the luminophore in a label-free ECL aptasensor. The novel AuPt nanodonuts were formed by decorating SnS2 QDs onto AuPt NR surfaces, which would promote the production of more coreactant intermediate in the SnS2 QDs/K2S2O8 system. As a result, the ECL performance was greatly improved. Meanwhile, l-cysteine (l-Cys) played an important role in the combination between AuPt NRs and SnS2 QDs, and the nanodonuts served as the matrix to load numerous lincomycin (Lin) aptamers. Under optimal conditions, the ECL aptasensor exhibited ultrasensitive detection of Lin from 1 fg/mL to 0.1 pg/mL with a limit of detection (LOD) of 0.7 fg/mL (1.72 fM).

Coronary artery fistula with or without aneurysm: A large comparative study.

Background: The knowledge of coronary artery fistula (CAF) with coronary aneurysm mostly comes from case reports and is very limited. However, the management of CAF with and without aneurysm is different, more understanding of its clinical and imaging features is necessary. This is the first research focus on it through a large comparative study. Purpose: To investigate the differences in imaging and clinical features of CAF with and without aneurysms. Methods: We reviewed 96,037 consecutive patients undergoing coronary computed tomography angiogram (CCTA) between 2016 and 2020 and total of 429 CAF adult patients were enrolled. Those patients were divided into the CAF with aneurysm group (321 cases, 74.83%) and CAF without aneurysm group (108 cases, 25.17%) according to whether complicated with coronary aneurysm. Clinical baseline data, electrocardiographic (ECG) characteristics, the presence or absence of coronary atherosclerosis, complication symptoms and fistulous origin, entry site, number and diameter were analyzed. Chi-square test, T-test, Mann-Whitney U tests, and logistic regression analysis were performed. Results: Most of the clinical baseline data did not differ significantly between the two groups (P > 0.05). However, heart murmur, coronary atherosclerosis, infective endocarditis (IE), fistulous diameter and fistulous entry site were significantly different (P＜0.05). Further multivariate logistic regression analysis showed that large fistulous diameter and coronary-cardiac chamber arterial fistulas was dependent risk factors for CAF complicated with aneurysm. Conclusion: CAF patients with aneurysm were more prone to develop heart murmur than those patients without aneurysm. Different from other sites of aneurysms, coronary atherosclerosis is more common in CAF without aneurysm. Larger fistulous diameter and coronary-cardiac chamber arterial fistula are dependent risk factors for CAF with aneurysms.

Swimming prevents cell death of chondrocytes via PI3K/AKT pathway in an experimental model.

BACKGROUND: Knee Osteoarthritis (KOA) is one of the main causes of disability in the elderly and with limited treatment options. Swimming was considered as an ideal form of non-surgical management of KOA. Nevertheless, the mechanism of swimming intervene OA remains unclear. ACLT induced OA model was often used to study the pathogenesis and treatment of OA. Thus, we evaluated the protective effect of swimming on KOA mouse and tried to explore the underlying mechanism. METHODS: Forty C57BL/6 mice were randomly divided into five groups: Blank group, ACLT group, ACLT + Swim group, Sham group and Sham + Swim group (n = 8). OA model was established by Anterior Cruciate Ligament Transection surgery (ACLT). After modeling, mice in ACLT + Swim and Sham + Swim groups were trained with a moderate swimming program, 5 d/week, for 6 weeks. HE and Safranin-O/fast staining, Immunohistochemistry, TUNEL assay and Western blot were used to detect the effect of swimming on pathological changes, cell death and the mechanism in KOA mouse. RESULTS: Swimming significantly enhanced CoII expression and suppressed ADAMTS5 expression in cartilage of KOA mouse, thus ameliorated KOA development. Apoptotic and autophagic processes were enhanced in OA cartilage, which might be caused by down-regulation of PI3K/AKT pathway; swimming could activate PI3K/AKT pathway and thus regulate apoptosis and autophagy processes of chondrocytes. CONCLUSION: Swimming could prevent cell death of chondrocytes via PI3K/AKT pathways, thus delayed the progression of KOA in an experimental model.

Benign prostatic hyperplasia associated with white matter hyperintensities in men.

PURPOSE: Benign prostatic hyperplasia (BPH) describes common noncancerous prostate enlargement. BPH is usually associated with lower urinary tract symptoms and an increased risk of cerebrovascular diseases, such as stroke and its recurrence. White matter hyperintensities (WMHs), markers of cerebral injury, increase the risk of stroke, cognitive impairment, dementia, and death. The relationship between BPH and WMHs remains unclear. This study aimed to determine the association between BPH and WMHs. METHODS: A total of 788 male patients from the First Affiliated Hospital of Kunming Medical University from July 2019 to September 2021 were enrolled in this cross-sectional study. BPH was assessed by abdominal ultrasound, and three independent neuroradiologists rated the presence or absence of WMHs. Multiple imputations of chained equations were used to handle missing data. Logistic regression was used to assess the relationship between BPH and WMHs. RESULTS: Patients with BPH presented an increased risk of WMHs with a crude odds ratio (OR) of 2.76 (95% CI, 2.02-3.79) and an adjusted OR of 1.75 (95% CI, 1.24-2.48) after controlling for potential confounding factors in the multivariate logistic regression. CONCLUSION: We found that BPH was closely associated with WMHs in male Chinese individuals.

Ultrasensitive determination of α-glucosidase activity using CoOOH nanozymes and its application to inhibitor screening.

In this work, a novel method for the colorimetric sensing of α-glucosidase (α-Glu) activity was developed based on CoOOH nanoflakes (NFs), which exhibit efficient oxidase-mimicking activity. Colorless 3,3',5,5'-tetramethylbenzidine (TMB) can be oxidized by CoOOH NFs into blue-colored oxidized TMB (oxTMB) in the absence of H2O2. L-Ascorbic acid-2-O-α-D-glucopyranose (AAG) can be hydrolysed by α-glucosidase to produce ascorbic acid, resulting in a significant decrease of catalytic activity of CoOOH NFs. Thus, a colorimetric α-glucosidase activity detection method was designed with a limit of detection of 0.0048 U mL-1. Furthermore, the designed sensing platform exhibits favorable applicability for the α-glucosidase (α-Glu) activity assay in real samples. Meanwhile, this method can be expanded to study the inhibitors of α-Glu. Finally, the as-proposed method combined with a smartphone would be a color recognizer, which was successfully applied for the determination of α-Glu activity in human serum samples.

Self-Powered Biosensor for a Highly Efficient and Ultrasensitive Dual-Biomarker Assay.

A dual-biomarker, self-powered biosensor was fabricated for the ultrasensitive detection of microRNA-21 (miRNA-21) and miRNA-155 based on enzymatic biofuel cells (EBFCs), catalytic hairpin assembly (CHA), and DNA hybridization chain reaction (HCR), with a capacitor and digital multimeter (DMM). In the presence of miRNA-21, the CHA and HCR are triggered and lead to the generation of a double-helix chain, which stimulates [Ru(NH3)6]3+ to move to the biocathode surface due to electrostatic interaction. Subsequently, the biocathode obtains electrons from the bioanode and reduces [Ru(NH3)6]3+ to [Ru(NH3)6]2+, which significantly increases the open-circuit voltage (E1OCV). When miRNA-155 is present, CHA and HCR cannot be completed, resulting in a low E2OCV. The self-powered biosensor allows for the simultaneous ultrasensitive detection of miRNA-21 and miRNA-155 with detection limits of 0.15 and 0.66 fM, respectively. Moreover, this self-powered biosensor exhibits the highly sensitive detection for miRNA-21 and miRNA-155 assay in human serum samples.

Associate factors for endoscopic submucosal dissection operation time and postoperative delayed hemorrhage of early gastric cancer.

BACKGROUND: Endoscopic submucosal dissection (ESD) is a treatment for early gastric cancer with the advantages of small invasion, fewer complications, and a low local recurrence rate. However, there is a high risk of complications such as bleeding and perforation, and the operation time is also longer. ESD operation time is closely related to bleeding and perforation. AIM: To investigate the influencing factors associated with ESD operation time and postoperative delayed hemorrhage to provide a reference for early planning, early identification, and prevention of complications. METHODS: We conducted a retrospective study based on the clinical data of 520 patients with early gastric cancer in the Second Affiliated Hospital of Hainan Medical University from January 2019 to December 2021. The baseline data, clinical features, and endoscopic and pathological characteristics of patients were collected. The multivariate linear regression model was used to investigate the influencing factors of ESD operation time. Logistic regression analysis was carried out to evaluate the influencing factors of postoperative delayed hemorrhage. RESULTS: The multivariate analysis of ESD operation time showed that the maximum lesion diameter could affect 8.815% of ESD operation time when other influencing factors remained unchanged. The operation time increased by 3.766% or 10.247% if the lesion was mixed or concave. The operation time increased by 4.417% if combined with an ulcer or scar. The operation time increased by 3.692% if combined with perforation. If infiltrated into the submucosa, it increased by 2.536%. Multivariate analysis of delayed hemorrhage after ESD showed that the maximum diameter of the lesion, lesion morphology, and ESD operation time were independent influencing factors for delayed hemorrhage after ESD. Patients with lesion ≥ 3.0 cm (OR = 3.785, 95%CI: 1.165-4.277), lesion morphology-concave (OR = 10.985, 95%CI: 2.133-35.381), and ESD operation time ≥ 60 min (OR = 2.958, 95%CI: 1.117-3.526) were prone to delayed hemorrhage after ESD. CONCLUSION: If the maximum diameter of the lesion in patients with early gastric cancer is ≥ 3.0 cm, and the shape of the lesion is concave, or accompanied by an ulcer or scar, combined with perforation, and infiltrates into the submucosa, the ESD operation will take a longer time. When the maximum diameter of the lesion is ≥ 3.0 cm, the shape of the lesion is concave in patients and the operation time of ESD takes longer time, the risk of delayed hemorrhage after ESD is higher.

Electrochemical skin conductance and heart rate variability in patients with non-dialysis chronic kidney disease.

BACKGROUND: Chronic kidney disease (CKD) is very common now and associates with high overall and cardiovascular mortality. Numerous studies have reported that Heart rate variability (HRV) could also be used to detect cardiovascular autonomic dysfunction (CAD). We investigated the association of electrochemical skin conductance (ESC) of EZSCAN results with HRV in non-dialysis CKD patients. METHODS: In a cross-sectional study, we enrolled 248 prevalent non-dialysis CKD patients. Patients underwent a 24-h Holter (CB-2302-A, Bio Instrument, China). A time domain analysis of HRV was performed, and the following parameters were obtained: SDNN, SDANN, rMSSD, pNN50. EZSCAN device (Impeto Medical, Paris, France) measures ESC values of each participants. Mean global skin conductance computed as 0.5 * (reflecting (right + left hand)/2 + (right and left foot)/2). Log transforms data into a normal distribution for statistical analysis. RESULTS: There were 142 males and 106 females included in the present study. Patients' age was 56.6±17.08 years. Logarithm(Log) (global ESC) was independently predicted by age (P<0.01), hypertension history, estimated Glomerular filtration rate (eGFR) and log SDNN (P<0.05). While log SDANN, rMSSD and pNN50 were not independent predictors for log (global ESC). CONCLUSION: Increased global ESC significantly associated with elevated HRV, specifically SDNN in non-dialysis CKD patients. This suggested that global ESC may appear to be an important predictor of CAD, and even could be used as a cardiovascular risk factor in non-dialysis CKD patients.

Hyperoside alleviates toxicity of ß-amyloid via endoplasmic reticulum-mitochondrial calcium signal transduction cascade in APP/PS1 double transgenic Alzheimer's disease mice.

Alzheimer's disease is a neurodegenerative disorder characterized by a decline in cognitive function. The ß-amyloid (Aß) hypothesis suggests that Aß peptides can spontaneously aggregate into ß-fragment-containing oligomers and protofibrils, and this activation of the amyloid pathway alters Ca2+ signaling in neurons, leading to neurotoxicity and thus apoptosis of neuronal cells. In our study, a blood-brain barrier crossing flavonol glycoside hyperoside was identified with anti-Aß aggregation, BACE inhibitory, and neuroprotective effect in cellular or APP/PSEN1 double transgenic Alzheimer's disease mice model. While our pharmacokinetic data confirmed that intranasal administration of hyperoside resulted in a higher bio-availability in mice brain, further in vivo studies revealed that it improved motor deficit, spatial memory and learning ability of APP/PSEN1 mice with reducing level of Aß plaques and GFAP in the cortex and hippocampus. Bioinformatics, computational docking and in vitro assay results suggested that hyperoside bind to Aß and interacted with ryanodine receptors, then regulated cellular apoptosis via endoplasmic reticulum-mitochondrial calcium (Ca2+) signaling pathway. Consistently, it was confirmed that hyperoside increased Bcl2, decreased Bax and cyto-c protein levels, and ameliorated neuronal cell death in both in vitro and in vivo model. By regulating Aß-induced cell death via regulation on Ca2+ signaling cascade and mitochondrial membrane potential, our study suggested that hyperoside may work as a potential therapeutic agent or preventive remedy for Alzheimer's disease.

Real-time multiple signal amplification self-powered biosensing platform for ultrasensitive detection of MicroRNA.

A real-time self-powered biosensor is designed for ultrasensitive detection of microRNA-21 based on electrochemical energy device capacitor and target-induced recycling double amplification strategy, which greatly improves the output signal by converting a small number of targets into two glucose oxidase labeled output strand DNAs, and the squeezed-out output strand is recycled by the cathode to fix more signal [Ru(NH3)6]3+ to further improve the detection signal. A digital multimeter (DMM) is connected to computer for real-time displaying the output signal of the self-powered biosensing system, which improves the accuracy of the sensing platform. The sensitivity of the proposed biosensor is 116.15 µA/pM for target microRNA-21, which is 32.26 times higher than that of pure EBFC (3.6 µA/pM). The target concentration is proportional to the open-circuit voltage value in a wide linear range of 0.1-10000 fM with a low detection limit of 0.04 fM (S/N = 3). The method shows high sensitivity and excellent selectivity, and can be applied to detect tumor marker microRNA-21 in biological matrix.