A case of pancreatic carcinosarcoma detected on PET/CT.

Primary pancreatic carcinosarcoma is a rare and malignant neoplasm composed of a mixture of sarcomatous and carcinomatous elements. With fewer than forty cases ever reported, the recognition of this rare phenomenon can be difficult. In the present case, a 73-year-old woman with pancreatitis underwent computed tomography which revealed wall-off pancreatic necrosis. Following initial and delayed fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) revealed high uptake of tracer in pancreatic mass, endoscopic biopsy revealed carcinosarcoma. The patient underwent laparoscopic pancreato-caudal resection and was confirmed to have pancreatic carcinosarcoma on microscopic evaluation. The case shows the importance of PET/CT on the early diagnosis in pancreatic mass, and suggests pancreatic carcinosarcoma should be considered as a possible differential diagnosis, which can hasten treatment and improve patient outcomes.

Successful pregnancy without disease progression of radioiodine refractory papillary thyroid carcinoma: a case report.

BACKGROUND: Pregnancy is an unquantifiable risk to accelerate tumor growth of papillary thyroid carcinoma (PTC), and whether pregnancy induces an unfavorable prognosis of radioiodine refractory papillary thyroid carcinoma (RR-PTC) remains unknown. CASE PRESENTATION: We investigated the impact of pregnancy on the prognosis of pulmonary metastases in an RR-PTC woman via a long-term clinical follow-up and consecutive computed tomography examinations and serum tests. After a successful pregnancy, the metastatic lesions shrank with serum thyroglobulin slightly fluctuated under sustained thyroid stimulating hormone (TSH) suppression, demonstrating a favorable outcome. CONCLUSIONS: This case study indicates that metastatic RR-PTC may not be aggravated by pregnancy under TSH suppression, and pregnancy should not be contraindicated in RR-PTC patients with stable disease.

Challenges and strategies on radioiodine treatment for differentiated thyroid carcinoma.

OBJECTIVE: Radioiodine ((131)I) is considered an effective and low-risk therapeutic radionuclide for differentiated thyroid carcinoma (DTC); however, dilemmas exist in the optimization of indications, pre-treatment thyroid stimulating hormone (TSH) stimulation, dose decision, as well as in the treatment of (131)I-refractory disease. Refined strategies on (131)I treatment for DTC based on late evidence and novel insights are greatly needed. CONCLUSION: The indications of (131)I ablation continue to be refined with a better understanding of the risks and benefits. For pre-treatment TSH stimulation, recombinant human thyrotropin presents a better choice as it improves the quality of life, but is indicated only for ablation of the thyroid remnant and follow-up. Decreased doses of (131)I seem to be more appropriate in patients without gross residual disease or metastases, but maximal doses are suggested in patients with advanced disease. Imaging procedures contributing to decision-making for patients with advanced DTC also continue to be modified. As for the (131)I-refractory disease, there is a trend to increase (131)I uptake and retention by using additional therapeutic agents like kinase inhibitors with encouraging results.

Pollution levels and characteristics of phthalate esters in indoor air of offices.

The pollution status and characteristics of PAEs (phthalate esters) were investigated in indoor air of offices, and PAEs of both gas-phase and particulate-phase were detected in all the samples. The concentration (sum of the gas phase and the particulate phase) was 4748.24 ng/m3, ranging between 3070.09 and 6700.14 ng/m3. Diethyl phthalate, dibutyl phthalate, and di(2-ethylhexyl) phthalate were the most abundant compounds, together accounting for 70% of the ∑6PAEs. Dividing the particulate-phase PAEs into four size ranges (<2.5, 2.5-5, 5-10, >10 µm), the result indicated that PAEs in PM2.5 were the most abundant, with the proportion of 72.64%. In addition, the PAE concentration in PM2.5 correlated significantly with the total particulate-phase PAEs (R2=0.85). Thus, the amount of PAEs in PM2.5 can be estimated from the total amount of particulate-phase PAEs using this proportion. In a comparison between the offices and a newly decorated study room, it was found that pollution characteristics were similar between these two places. Thus, it is implied that the PAE concentration decreased by 50% 2 yr after decorating.

A marine oil spill detection framework considering special disturbances using Sentinel-1 data in the Suez Canal.

The Suez Canal is a crucial international waterway due to its strategic location. The significant traffic flow not only stimulates economic development along the coast but also leads to a high frequency of oil spill accidents, which negatively impact the ecosystem and natural resources. Synthetic aperture radar (SAR) is an important remote sensing technology for monitoring oil spills, offering all-day and all-weather capabilities. However, special disturbances (SD) caused by imaging conditions, sensor parameters, and other factors can affect image quality, reducing the accuracy and efficiency of oil spill detection. To mitigate the negative impact of SD, an original oil spill detection framework was developed, based on the analysis of these disturbances, to detect oil spills at the northern entrance of the Suez Canal from 2015 to 2019. The framework included an advantageous featureset with SD adaptability and designs a classifier, Boosting Random Support Vector Machine (BRSVM), which combines a boosting strategy with Support Vector Machine (SVM). The study found that the superiority of the featureset was pivotal in oil spill detection. The classification accuracy and F-1 score achieved by BRSVM were 94.72 % and 95.33 %, respectively, outperforming other algorithms in functionality. These results indicate that the proposed framework holds significant potential for applications requiring large-scale, automated oil spill detection.

Disposable electrochemiluminescent biosensor using bidentate-chelated CdTe quantum dots as emitters for sensitive detection of glucose.

A novel disposable solid-state electrochemiluminescent (ECL) biosensor was fabricated by immobilizing glucose oxidase and surface-unpassivated CdTe quantum dots (QDs) on a screen-printed carbon electrode (SPCE). The surface morphology of the biosensor was characterized with scanning electron microscopy and atomic force microscopy. With dissolved O(2) as an endogenous coreactant, QDs/SPCE showed strong ECL emission in pH 9.0 HCl-Tris buffer solution with low ECL peak potential at -0.89 V. The ECL intensity was twice that with hydrogen peroxide as coreactant at the same concentration. This phenomenon meant the ECL decreased upon consumption of dissolved O(2) and thus could be applied to the construction of oxidase-based ECL biosensors. With glucose oxidase as a model enzyme, the biosensor showed rapid response to glucose with a linear range of 0.8 to 100 µM and a detection limit of 0.3 µM. Further detection of glucose contained in human serum samples showed acceptable sensitivity and selectivity. This work provided a promising application of QDs in ECL-based disposable biosensors.

Transformation of lymphoid interstitial pneumonia (LIP) into malignant lymphoma in patients with Sjogren's syndrome: a case report and literature review.

BACKGROUND: Lymphoid interstitial pneumonia (LIP) is a very rare disease and its malignant transformation is even more rare. LIP is easily misdiagnosed by clinicians and radiologists. CASE PRESENTATION: The medical record of a 64-year-old female with Sjogren's syndrome was reviewed. The clinical and pathological data along with chest CT images were obtained. The literature related to the transformation was reviewed. There were no specific clinical manifestations of LIP and its transformation into malignant lymphoma in the patient. The chest CT mainly displayed multiple cystic foci, with multiple nodules and ground-glass shadows in both lungs. CONCLUSIONS: Malignant transformation to lymphoma is suspected with findings of large nodules (> 11 mm) or their sizes doubly increased, pleural effusion and alveolar consolidation.

Graphene and its Derivatives-Based Optical Sensors.

Being the first successfully prepared two-dimensional material, graphene has attracted extensive attention from researchers due to its excellent properties and extremely wide range of applications. In particular, graphene and its derivatives have displayed several ideal properties, including broadband light absorption, ability to quench fluorescence, excellent biocompatibility, and strong polarization-dependent effects, thus emerging as one of the most popular platforms for optical sensors. Graphene and its derivatives-based optical sensors have numerous advantages, such as high sensitivity, low-cost, fast response time, and small dimensions. In this review, recent developments in graphene and its derivatives-based optical sensors are summarized, covering aspects related to fluorescence, graphene-based substrates for surface-enhanced Raman scattering (SERS), optical fiber biological sensors, and other kinds of graphene-based optical sensors. Various sensing applications, such as single-cell detection, cancer diagnosis, protein, and DNA sensing, are introduced and discussed systematically. Finally, a summary and roadmap of current and future trends are presented in order to provide a prospect for the development of graphene and its derivatives-based optical sensors.

Low-potential electrochemiluminescent sensing based on surface unpassivation of CdTe quantum dots and competition of analyte cation to stabilizer.

A novel electrochemiluminescent (ECL) sensing system was constructed for low-potential detection of metal ion by immobilizing surface-unpassivated CdTe quantum dots (QDs) on a glassy carbon electrode. The surface-unpassivated CdTe QDs were prepared using meso-2,3-dimercaptosuccinic acid (DMSA) as a stabilizer to cap CdTe QDs and characterized with scanning electron micrograph and X-ray photoelectron spectroscopy. The immobilized QDs showed a strong cathodic ECL emission peak at -0.87 V with an onset potential at -0.64 V (vs Ag/AgCl/saturated KCl) in air-saturated, pH 9.0 HCl-Tris buffer. On the basis of the competition of metal ion to the stabilizer, the quenching effect of metal ion on ECL emission was observed, which led to a sensitive chemical sensing application. Using cupric cation as a model analyte, the sensor showed a linear range from 5.0 nM to 7.0 muM with a detection limit of 3.0 nM and had been successfully applied in the detection of copper in human hair. It could be extended to detect other metal ions with stronger metal-S interaction than with the Cd-S bond. As an example, the sensor could be used to detect Hg(2+) down to 1.4 nM. The bidentate chelate QD-based sensor exhibited a promising platform for rapid detection of cations with strong metal-S interaction and could be further applied for development of other low-potential electrochemical sensing systems.

Quantum dots based electrochemiluminescent immunosensor by coupling enzymatic amplification with self-produced coreactant from oxygen reduction.

A highly sensitive competitive immunosensor based on the electrochemiluminescence (ECL) of quantum dots (QDs) was proposed by coupling with an enzymatic amplification. The fabrication process of the immunosensor was traced with atomic force microscopic images and electrochemical impedance spectra. The strong cathodic ECL emission of the immobilized QDs could be detected at a relatively low emission potential. The reduction of dissolved oxygen during the cathodic process provided a self-produced coreactant, H(2)O(2), for the ECL emission. Using human IgG (HIgG) as a model protein, upon the immuno-recognition of the immobilized HIgG to its antibody labeled simply with horseradish peroxidase, the ECL intensity decreased due to the steric hindrance of the proteins to electron transfer. The decrease could be greatly amplified by an enzymatic cycle to consume the self-produced coreactant, leading to a wide calibration range of 0.05 ng mL(-1) approximately 5 microg mL(-1) and a low limit of detection for the competitive immunoassay of HIgG. This immunosensor showed good stability and fabrication reproducibility. The immunoassays of practical samples showed acceptable results. This facile immunosensing strategy opened a new avenue for detection of proteins and application of QDs in ECL biosensing.

Formation of surface traps on quantum dots by bidentate chelation and their application in low-potential electrochemiluminescent biosensing.

Bidentate chelation, meso-2,3-dimercaptosuccinic acid (DMSA), was used as a stabilizer for the synthesis of CdTe quantum dots (QDs). The bidentate chelate QDs, characterized with FT-IR, PL, and UV/Vis spectroscopy; element analysis; and high-resolution transmission electron microscope, exhibited surface traps due to the large surface/volume ratio of QD particle and the steric hindrance of the DMSA molecule. The unpassivated surface of the QDs produced a narrower band gap than the core and electrochemiluminescent (ECL) emission at relatively low cathodic potential. In air-saturated pH 7.0 buffer, the QDs immobilized on electrode surface showed an intense ECL emission peak at -0.85 V (vs. Ag/AgCl). H(2)O(2) produced from electrochemical reduction of dissolved oxygen was demonstrated to be the co-reactant, which avoided the need of strong oxidant as the co-reactant and produced a sensitive analytical method for peroxidase-related analytes. Using hydroquinone/horseradish peroxidase/H(2)O(2) as a model system, a new, reagentless, phenolic, ECL biosensor for hydroquinone was constructed, based on the quenching effect of ECL emission of QDs by consumption of co-reactant H(2)O(2). The biosensor showed a linear range of 0.2-10 µM with acceptable stability and reproducibility. This work opens new avenues in the search for new ECL emitters with excellent analytical performance and makes QDs a more attractive alternative in biosensing.

MAPK Inhibitors Enhance HDAC Inhibitor-Induced Redifferentiation in Papillary Thyroid Cancer Cells Harboring BRAF V600E: An In Vitro Study.

Clinical efficacy of redifferentiation therapy with histone deacetylase inhibitor (HDACi) for lethal radioiodine-refractory papillary thyroid cancer (RR-PTC) is urgently needed to be improved. Given that the impairment of histone acetylation is a mechanism in BRAF V600E-mitogen-activated protein kinase (MAPK)-induced aberrant silencing of thyroid iodine-metabolizing genes, dual inhibition of HDAC and MAPK may produce a more favorable effect. In this study, we treated BRAF V600E-mutant (BCPAP and K1) and BRAF-wild-type (BHP 2-7) cells with HDACi (panobinostat) and MAPK inhibitor (dabrafenib or selumetinib), alone or in combination, and we tested the expression of iodine- and glucose-metabolizing genes, radioiodine uptake and efflux, and toxicity. We found that panobinostat alone increased iodine-metabolizing gene expression, promoted radioiodine uptake and toxicity, and suppressed GLUT1 expression in all the cells. However, MAPKi (dabrafenib or selumetinib) induced these effects only in BRAF V600E-mutant cells. Combined treatment with panobinostat and MAPKi (dabrafenib or selumetinib) displayed a more robust BRAF V600E-dependent redifferentiation effect than panobinostat alone via further improving the acetylation level of histone at the sodium-iodide symporter (NIS) promoter. In conclusion, MAPK inhibitors enhance HDACi-induced redifferentiation in PTC cells harboring BRAF V600E, warranting animal and clinical trials.

Radioiodine Uptake and Thyroglobulin-Guided Radioiodine Remnant Ablation in Patients with Differentiated Thyroid Cancer: A Prospective, Randomized, Open-Label, Controlled Trial.

BACKGROUND: Radioiodine (131I) remnant ablation (RRA) has become a key step in the postoperative treatment of differentiated thyroid cancer (DTC). However, inadequate or excessive 131I is common using fixed activities. This study was designed to explore the feasibility of radioiodine uptake and thyroglobulin (RAIU-Tg)-guided RRA. METHODS: A total of 277 patients were randomized to the RAIU-Tg-based activity group or a fixed activity of 3.7 GBq group at a ratio of 4:1. The RAIU-Tg-based activity was established based on four levels of RAIU (≤2%, 2-5%, 5-15%, and >15%) and Tg levels (≤2, 2-5, 5-10, and >10 ng/mL). Based on this, 131I activities of 1.1, 1.85, 3.7, and 5.55 GBq were administered. If the levels for RAIU and Tg were not in the same category, the higher activity determined by either RAIU or Tg was administered. Successful RRA was defined as negative diagnostic whole-body scan and Tg <1 ng/mL (anti-Tg antibody negative) or negative diagnostic whole-body scan (anti-Tg antibody positive) under thyrotropin stimulation six months or more post RRA. RESULTS: There was no statistically significant difference in baseline characteristics between the RAIU-Tg-based activity group (n = 207) and the fixed activity group (n = 58). The activity of 131I used in the RAIU-Tg-based activity group (3.26 ± 1.54 GBq) was significantly lower than that used in the fixed activity group (p < 0.0001), whereas the rate of successful RRA in the RAIU-Tg-based activity group was significantly higher than the rate in the fixed activity group (94.2% vs. 70.7%; p < 0.0001). The rates of successful RRA in the four subgroups of the RAIU-Tg-based activity group were comparable (p = 0.543). Although there was no statistically significant difference in the incidence of total/short-term adverse effects between the RAIU-Tg-based activity group and the fixed activity group, a significantly lower incidence of intermediate adverse effects, which predominantly consisted of xerostomia, was reported in the RAIU-Tg-based activity group. CONCLUSIONS: Compared to a fixed activity of 3.7 GBq, RAIU-Tg-guided dosimetry can improve the success rate and decrease the incidence of intermediate side effects of RRA in postoperative patients with DTC.

Dopamine detection based on its quenching effect on the anodic electrochemiluminescence of CdSe quantum dots.

Anodic electrochemiluminescence (ECL) of CdSe quantum dots (QDs) in a neutral system was for the first time observed at a relatively low potential by using sulfite as a co-reactant to produce the ECL emission at an indium tin oxide (ITO) electrode, which could be used for the sensitive detection of ECL quenchers using dopamine (DA) as a model molecule.

Radioiodine refractory differentiated thyroid cancer.

Differentiated thyroid cancer (DTC) is usually curable with surgery, radioactive iodine (RAI), and thyroid-stimulating hormone (TSH) suppression. However, local recurrence and/or distant metastases occur in approximately 15% of cases during follow-up, and nearly two-thirds of these patients will become RAI-refractory (RR-DTC) with a poor prognosis. This review focuses on the most challenging and rapidly evolving aspects of RR-DTC, and we discuss the considerable improvement in more accurately defining RR-DTC, more effective therapeutic strategies, and describe the diagnosis, pathogenesis, and future prospects of RR-DTC. Along with the detection of serum thyroglobulin and anatomic imaging modalities, such as ultrasound and computer tomography, radionuclide molecular imaging plays a vital role in the evaluation of RR-DTC. In addition, continual progress has been made in the management of RR-DTC, including watchful waiting under appropriate TSH suppression, local treatment approaches, and systemic therapies (molecular targeted therapy, redifferentiation therapy, gene therapy, and cancer immunotherapy). These all hold promise to change the natural history of RR-DTC.

Predicting 131I-avidity of metastases from differentiated thyroid cancer using 18F-FDG PET/CT in postoperative patients with elevated thyroglobulin.

The quantitative relationship between iodine and glucose metabolism in metastases from differentiated thyroid cancer (DTC) remains unknown. Aim of the prospective study was to establish the value of 18F-FDG PET/CT in predicting 131I-avidity of metastases from DTC before the first radioiodine therapy. A total of 121 postoperative DTC patients with elevated stimulated serum thyroglobulin (ssTg) who underwent 131I adjuvant therapy or therapy after 18F-FDG PET/CT scan were enrolled. The Receiver operating characteristic curve was established to create an optimal cut-off point and evaluate the value of SUVmax for predicting 131I-avidity. In our study, the median SUVmax in 131I-nonavid metastatic target lesions was also significantly higher than that in 131I-avid metastatic target lesions (5.37 vs. 3.30; P = 0.000). At a cut-off value of 4.0 in SUVmax, the area under curve was 0.62 with the sensitivity, specificity, positive predictive value and negative predictive value of 75.3%, 56.7%, 76.1%, and 54.8%, respectively. These results suggest that 18F-FDG PET/CT may be of great value in identifying metastases in postoperative DTC patients with elevated ssTg before 131I administration, leading to an improved management of disease. 18F-FDG positive metastatic DTC with SUVmax of greater than 4.0 possesses higher probability of non-avidity to radioiodine.

HER inhibitor promotes BRAF/MEK inhibitor-induced redifferentiation in papillary thyroid cancer harboring BRAFV600E.

Redifferentiation therapy with BRAF/MEK inhibitors to facilitate treatment with radioiodine represents a good choice for radioiodine-refractory differentiated thyroid carcinoma, but recent initial clinical outcomes were modest. MAPK rebound caused by BRAF/MEK inhibitors-induced activation of HER2/HER3 is a resistance mechanism, and combination with HER inhibitor to prevent MAPK rebound may sensitize BRAFV600E-mutant thyroid cancer cells to redifferentiation therapy. To evaluate if inhibiting both BRAF/MEK and HER can produce stronger redifferetiation effect, we tested the effects of BRAF/MEK inhibitor dabrafenib/selumetinib alone or in combination with HER inhibitor lapatinib on the expression and function of iodine- and glucose-handling genes in BRAFV600E-positive BCPAP and K1 cells, using BHP 2-7 cells harboring RET/PTC1 rearrangement as control. Herein, we showed that lapatinib prevented MAPK rebound and sensitized BRAFV600E-positive papillary thyroid cancer cells to BRAF/MEK inhibitors. Dabrafenib/selumetinib alone increased iodine-uptake and toxicity and suppressed glucose-metablism in BRAFV600E-positive papillary thyroid cancer cells. When lapatinib was added, more significant effects on iodine- and glucose-handling gene expression, cell membrane location of sodium/iodine symporter as well as radioiodine uptake and toxicity were observed. Thus, combined therapy using HER inhibitor and BRAF/MEK inhibitor presented more significant redifferentiation effect on papillary thyroid cancer cells harboring BRAFV600E than BRAF/MEK inhibitor alone. In vivo and clinical studies assessing such combined targeted redifferentiation strategy were warranted.

99mTc-pertechnetate-avid metastases from differentiated thyroid cancer are prone to benefit from 131I therapy: A prospective observational study.

The aim of this study is to determine the contribution of neck and chest Tc-pertechnetate scan to the management of postoperative patients with suspicious metastatic differentiated thyroid cancer (DTC), particularly to the prediction of response to radioiodine (I) therapy. Just before I administration, a total of 184 postoperative DTC patients with stimulated serum thyroglobulin (ssTg) >10 ng/mL were enrolled to undergo neck and chest Tc-pertechnetate scan, which were directly compared with post-therapeutic I scan to determine the concordance of site and number of metastatic lesions. The percentage changes in ssTg between Tc-pertechnetate-avid group and Tc-pertechnetate-nonavid group were compared, and the response to I in both groups was analyzed according to the nature of Tc-pertechnetate avidity as well. The percentages of concordance between Tc-pertechnetate and I scan in detecting metastases were 65.7% and 26.0% in per-patient and per-site analyses with low unweighted kappa, respectively. Tc-pertechnetate scan led to a change in therapeutic decision making in 19/184 (10.3%) patients. In 72 patients with I-avid metastases, the ssTg in Tc-pertechnetate-avid group (n = 13) decreased significantly compared with that in Tc-pertechnetate-nonavid group (n = 59) (median: -81.56% vs -48.14%; Z = -4.276, P = .000). The difference of therapeutic response between Tc-pertechnetate-avid group and Tc-pertechnetate-nonavid group was statistically significant (χ = 8.4; P = .03). Although the consistency between Tc-pertechnetate scan before I administration and post-therapy I scan in detecting metastases is low, identifying metastases in postoperative DTC patients with elevated ssTg via Tc-pertechnetate scan prior to I therapy provides incremental value for therapeutic decision making. Notably, patients with Tc-pertechnetate-avid metastases may be more prone to benefit from I therapy than those with Tc-pertechnetate-nonavid metastases.

Increased 18F-FDG uptake of heterotopic pancreatitis in the small intestine: A CARE-compliant case report.

BACKGROUD: Heterotopic pancreas (HP), a relatively uncommon congenital anomaly, is rarely noted during F-FDG positron-emission tomography/computed tomography (PET/CT) scan. METHODS: A 60-year-old woman was referred to our hospital due to a 10-day history of abdominal pain with elevated levels of serum amylase and lipase. Abdominal CT and ultrasound examinations were negative. In order to search for the cause, an F-FDG PET/CT whole body scan was suggested to an old woman revealing the presence of F-FDG accumulating nodule in small intestine. RESULTS: Surgical findings and pathologic results confirmed the diagnosis of small intestinal heterotopic pancreas with active chronic inflammation. CONCLUSION: This uncommon case underscores the necessity of considering heterotopic pancreatitis in small intestine with focal F-FDG uptake as a possible differential diagnosis in intestinal tumor and tuberculosis.

Label-free electrochemiluminescent detection of DNA by hybridization with a molecular beacon to form hemin/G-quadruplex architecture for signal inhibition.

A facile label-free electrochemiluminescent (ECL) DNA sensor was designed using a molecular beacon with a guanine-rich stem as a recognition probe. The ECL emission was produced from surface unpassivated CdTe quantum dots (QDs) co-immobilized with colloidal gold nanoparticles (AuNPs) on a chitosan-modified electrode surface. The molecular beacon was adsorbed onto the AuNPs by the thiolated stem. Upon the hybridization of the molecular beacon with target DNA to open the cycle in the presence of hemin, the dissociated guanine-rich sequence could conjugate hemin to form a G-quadruplex architecture. The formed DNAzyme then catalyzed the reduction of dissolved oxygen, the endogenous coreactant for ECL emission of QDs, leading to a decrease in ECL signal. The variations in surface morphology during the fabrication and recognition processes of the ECL sensor were characterized by atomic force microscopy and electrochemical impedance spectroscopy. The ECL signal inhibition depended linearly on the logarithmic value of DNA concentration ranging from 5.0 fM to 0.1 nM, with a detection limit of 0.9 fM. This proposed label-free method is a promising application of QDs-based ECL emission for ultrasensitive DNA assay.