A Portable Device for in Situ Noninvasive Monitoring of Cell Secretions and Communications with Fluorescence and Nanochannel Electrochemistry.

In situ monitoring of cell secretions and communications plays a fundamental role in screening of disease diagnostic biomarkers and drugs. Quantitative detection of cell secretions and monitoring of intercellular communication have been separately reported, which often rely on target labeling or complex pretreatment steps, inevitably causing damage to the target. Simultaneous in situ noninvasive detection of cell secretions and monitoring of intercellular communication are challenging and have never been reported. Herein, we smartly developed a portable device for in situ label-free monitoring of cell secretions and communications with fluorescence and ion-transport-based nanochannel electrochemistry. Based on the dual signal mode, a series of nonelectroactive secretions were sensitively and accurately quantified. The detection limits for VEGF, MUC1, and ATP were 3.84 pg/mL, 32.7 pg/mL, and 47.4 fM (3σ/S), which were 1/3.9, 1/1.1, and 1/41 of those of commercial ELISA kits, respectively. More interestingly, under the released secretions, the gradual opening of the nanochannel connected the two cells in the left and right chambers of the device; thus, the secretion mediated intercellular communication can be monitored. The proposed platform may provide a promising tool for understanding the mechanism of intercellular communication and discovering new therapeutic targets.

Versatile Metal-Organic Framework Incorporating Ag2S for Constructing a Photoelectrochemical Immunosensor for Two Breast Cancer Markers.

Breast cancer poses the significance of early diagnosis and treatment. Here, we developed an innovative photoelectrochemical (PEC) immunosensor characterized by high-level dual photocurrent signals and exceptional sensitivity. The PEC sensor, denoted as MIL&Ag2S, was constructed by incorporating Ag2S into a metal-organic framework of MIL-101(Cr). This composite not only enhanced electron-hole separation and conductivity but also yielded robust and stable dual photocurrent signals. Through the implementation of signal switching, we achieved the combined detection of cancer antigen 15-3 (CA15-3) and carcinoembryonic antigen (CEA) with outstanding stability, reproducibility, and specificity. The results revealed a linear range for CEA detection spanning 0.01-32 ng/mL, with a remarkably low detection limit of 0.0023 ng/mL. Similarly, for CA15-3 detection, the linear range extended from 0.1 to 320 U/mL, with a low detection limit of 0.014 U/mL. The proposed strategy introduces new avenues for the development of highly efficient, cost-effective, and user-friendly PEC sensors. Furthermore, it holds promising prospects for early clinical diagnosis, contributing to potential breakthroughs in medical detection and ultimately improving patient outcomes.

Target-Triggered Aggregation of Modified E. coli for Diagnosis of Ovarian Cancer.

Bacteria inherently possess the capability of quorum sensing in response to the environment. In this work, we have proposed a strategy to confer bacteria with the ability to recognize targets with quorum-sensing behavior. Meanwhile, we have successfully achieved artificial control over the target-triggered aggregation of Escherichia coli (E. coli) by modifying the bacteria surface in a new way. Furthermore, by making use of green fluorescent protein (GFP) expressed by E. coli as the output signal, the aggregation of modified E. coli can be observed with the naked eye. Therefore, via the detection of the target, MUC1, an ovarian cancer biomarker, a simple and conveniently operated method to diagnose ovarian cancer is developed in this work. Experimental results show that the developed low-background and enzyme-free amplification method enables the highly sensitive detection of MUC1, achieving a remarkable limit of detection (LOD) of 5.47 fM and a linear detection range spanning from 1 pM to 50 nM and 50 nM to 100 nM, respectively. Clinical samples from healthy donors and patients can give distant assay results, showing great potential for clinical applications of this method.

Intelligent Cell Profiling and Precision Release: Multimolecular Marker-Activated Transmembrane DNA Computing Nanosystem.

Accurate classification of tumor cells is of importance for cancer diagnosis and further therapy. In this study, we develop multimolecular marker-activated transmembrane DNA computing systems (MTD). Employing the cell membrane as a native gate, the MTD system enables direct signal output following simple spatial events of "transmembrane" and "in-cell target encounter", bypassing the need of multistep signal conversion. The MTD system comprises two intelligent nanorobots capable of independently sensing three molecular markers (MUC1, EpCAM, and miR-21), resulting in comprehensive analysis. Our AND-AND logic-gated system (MTDAND-AND) demonstrates exceptional specificity, allowing targeted release of drug-DNA specifically in MCF-7 cells. Furthermore, the transformed OR-AND logic-gated system (MTDOR-AND) exhibits broader adaptability, facilitating the release of drug-DNA in three positive cancer cell lines (MCF-7, HeLa, and HepG2). Importantly, MTDAND-AND and MTDOR-AND, while possessing distinct personalized therapeutic potential, share the ability of outputting three imaging signals without any intermediate conversion steps. This feature ensures precise classification cross diverse cells (MCF-7, HeLa, HepG2, and MCF-10A), even in mixed populations. This study provides a straightforward yet effective solution to augment the versatility and precision of DNA computing systems, advancing their potential applications in biomedical diagnostic and therapeutic research.

A multifunctional N-GO/PtCo nanocomposite bridged carbon fiber interface for the electrochemical aptasensing of CA15-3 oncomarker.

The development of integrated analytical devices is crucial for advancing next-generation point-of-care platforms. Herein, we describe a facile synthesis of a strongly catalytic and durable Nitrogen-doped graphene oxide decorated platinum cobalt (NGO-PtCo) nanocomposite that is conjugated with target-specific DNA aptamer (i-e. MUC1) and grown on carbon fiber. Benefitting from the combined features of the high electrochemical surface area of N-doped GO, high capacitance and stabilization by Co, and high kinetic performance by Pt, a robust, multifunctional, and flexible nanotransducer surface was created. The designed platform was applied for the specific detection of a blood-based oncomarker, CA15-3. The electrochemical characterization proved that nanosurface provides a highly conductive and proficient immobilization support with a strong bio-affinity towards MUC1 aptamer. The specific interaction between CA15-3 and the aptamer alters the surface properties of the aptasensor and the electroactive signal probe generated a remarkable increase in signal intensity. The sensor exhibited a wide dynamic range of 5.0 × 10-2 -200 U mL-1, a low limit of detection (LOD) of 4.1 × 10-2 U mL-1, and good reproducibility. The analysis of spiked serum samples revealed outstanding recoveries of up to 100.03 %, by the proposed aptasensor. The aptasensor design opens new revelations in the reliable detection of tumor biomarkers for timely cancer diagnosis.

Construction of a DNA walker nanomachine aptasensor for simultaneous detection of dual-cancer biomarkers.

While it is recognized that early diagnosis of cancer-related biomarkers can become an effective avenue for timely treatment and successfully improve patient survival, it remains challenging to get accurate inspection results. Currently, most reported cancer biomarker sensing methods are focused on the quantitative detection of a single type of biomarker, which makes accurate medical diagnostics difficult. In this work, we constructed a DNA walker nanomachine aptasensor based on gold nanoparticles for the simultaneous sensing of dual cancer biomarkers. The aptamers, labelled with a fluorophore, hybridized with complementary strands on the gold nanoparticle surface, serve as a walking track. Target analytes bind to their specific aptamers, leading to the dissociation of the unstable double-strand spherical nucleic acid. Exonuclease I (Exo I) selectively digested the aptamers bound with the target analytes, then the released targets go back to the next apamers on the gold nanopareticles surface for walking. The use of spherical nucleic acid probes improved the sensitivity of analyte detection. Exo I provided a driving power for target recycling and considerably improved the sensitivity of the aptasensor as well. The DNA walker nanomachine aptasensor was successfully applied for the detection of carcinoembryonic antigen (CEA) in the range of 0.167 to 3.34 ng mL-1, and mucin-1 (MUC-1) in the same range. Moreover, we used the two aptamers to construct the DNA walker nanomachine and achieved the simultaneous detection of CEA and MUC-1, thus having great potential for biomolecular logic gate construction and early disease diagnosis.

Enhancing electrochemical detection through machine learning-driven prediction for canine mammary tumor biomarker with green silver nanoparticles.

This study developed an innovative biosensor strategy for the sensitive and selective detection of canine mammary tumor biomarkers, cancer antigen 15-3 (CA 15-3) and mucin 1 (MUC-1), integrating green silver nanoparticles (GAgNPs) with machine learning (ML) algorithms to achieve high diagnostic accuracy and potential for noninvasive early detection. The GAgNPs-enhanced electrochemical biosensor demonstrated selective detection of CA 15-3 in serum and MUC-1 in tissue homogenates, with limits of detection (LODs) of 0.07 and 0.11 U mL-1, respectively. The nanoscale dimensions of the GAgNPs endowed them with electrochemically active surface areas, facilitating sensitive biomarker detection. Experimental studies targeted CA 15-3 and MUC-1 biomarkers in clinical samples, and the biosensor exhibited ease of use and good selectivity. Furthermore, ML algorithms were employed to analyze the electrochemical data and predict biomarker concentrations, enhancing the diagnostic accuracy. The Random Forest algorithm achieved 98% accuracy in tumor presence prediction, while an Artificial Neural Network attained 76% accuracy in CA 15-3-based tumor grade classification. The integration of ML techniques with the GAgNPs-based biosensor offers a promising approach for noninvasive, accurate, and early detection of canine mammary tumors, potentially revolutionizing veterinary diagnostics. This multilayered strategy, combining eco-friendly nanomaterials, electrochemical sensing, and ML algorithms, holds significant potential for advancing both biomedical research and clinical practice in the field of canine mammary tumor diagnostics.

Prognostic performance of Krebs von den Lungen-6, surfactant protein A, surfactant protein D levels in the serum and bronchoalveolar lavage fluid in chronic fibrosing interstitial pneumonia: a retrospective study.

BACKGROUND: The serum markers Krebs von den Lungen-6 (KL-6), surfactant protein A (SP-A), and surfactant protein D (SP-D) have been used for the diagnosis, differential diagnosis, and prognosis prediction of interstitial pneumonia. However, the significance of measuring the serum and bronchoalveolar lavage fluid (BALF) KL-6, SP-D, and SP-A levels in predicting the prognosis of chronic fibrosing interstitial pneumonia (CFIP), idiopathic pulmonary fibrosis, and idiopathic nonspecific interstitial pneumonia remains unclear. We aimed to clarify the significance of measuring the serum and BALF KL-6, SP-A, and SP-D levels in predicting the prognosis of patients with CFIP. METHODS: Among 173 patients who were diagnosed with CFIP between September 2008 and February 2021, 39 who underwent bronchoalveolar lavage were included in this study. Among these, patients experiencing an annual decrease in forced vital capacity (FVC) of ≥10% or those facing challenges in undergoing follow-up pulmonary function tests owing to significant deterioration in pulmonary function were categorized as the rapidly progress group. Conversely, individuals with an annual decrease in the FVC of <10% were classified into the slowly progress group. The serum and BALF KL-6, SP-D, and SP-A levels, as well as BALF/serum SP-D and SP-A ratios were compared between the two groups. RESULTS: Among the patients with CFIP, the BALF SP-D level (p=0.0111), BALF SP-A level (p<0.0010), BALF/serum SP-D ratio (p=0.0051), and BALF/serum SP-A ratio (p<0.0010) were significantly lower in the rapidly than in the slowly progress group (p<0.0010). The receiver operating characteristics analysis results demonstrated excellent performance for diagnosing patients with CFIP, with the BALF SP-D level (area under the curve [AUC], 0.7424), BALF SP-A level (AUC, 0.8842), BALF/serum SP-D ratio (AUC, 0.7673), and BALF/serum SP-A ratio (AUC, 0.8556). Moreover, the BALF SP-A level showed a notably superior CFIP diagnostic capability. Survival analysis using the Kaplan-Meier method revealed that patients with a BALF SP-A level of <1500 ng/mL and BALF/serum SP-A ratio of <15.0 had poor prognoses. CONCLUSIONS: Our results suggest that BALF SP-A measurement may be useful for predicting the prognosis in patients with CFIP.

EMA-Positive Superficial ALK-Rearranged Myxoid Spindle Cell Neoplasm Masquerading as Perineurioma/Hybrid Nerve Sheath Tumor.

ABSTRACT: Superficial anaplastic lymphoma kinase (ALK)-rearranged myxoid spindle cell neoplasm (SAMS) is a recently described entity which coexpresses ALK, CD34, and commonly S100. These neoplasms are characterized morphologically by concentric spindle cell whorls and cords and are commonly set in an abundant myxoid to myxocollagenous stroma, thus mimicking perineurioma or hybrid nerve sheath tumor. EMA immunostain has been reported to be negative in SAMS which helps in excluding the latter entities. Herein, we report the first EMA-positive SAMS of the right leg in a 37-year-old female patient masquerading as perineurioma/hybrid nerve sheath tumor. The tumor morphologically was comprised of spindle cells arranged in loose whorls and short fascicles set in myxoid to collagenous stroma and coexpressed CD34 and EMA, reminiscent of perineurioma. S100 showed focal staining. ALK immunostain was subsequently performed and was positive. ALK gene rearrangement was identified by fluorescence in situ hybridization break-apart assay and was further confirmed by next-generation sequencing-based RNA sequencing demonstrating FLNA::ALK fusion, thus supporting the diagnosis of SAMS. In conclusion, EMA can be expressed in SAMS, thus posing as a diagnostic pitfall. ALK immunostain and molecular studies are essential for confirming the diagnosis of SAMS and excluding potential mimickers, particularly perineurioma or hybrid nerve sheath tumor.

Atomically Co-dispersed nitrogen-doped carbon for sensitive electrochemical immunoassay of breast cancer biomarker CA15-3.

The development of an ultrasensitive and precise measurement of a breast cancer biomarker (cancer antigen 15-3; CA15-3) in complex human serum is essential for the early diagnosis of cancer in groups of healthy populations and the treatment of patients. However, currently available testing technologies suffer from insufficient sensitivity toward CA15-3, which severely limits early large-scale screening of breast cancer patients. We report a versatile electrochemical immunoassay method based on atomically cobalt-dispersed nitrogen-doped carbon (Co-NC)-modified disposable screen-printed carbon electrode (SPCE) with alkaline phosphatase (ALP) and its metabolite, ascorbic acid 2-phosphate (AAP), as the electrochemical labeling and redox signaling unit for sensitive detection of low-abundance CA15-3. During electrochemical detection by differential pulse voltammetry (DPV), it was found that the Co-NC-SPCE electrode did not have a current signal response to the AAP substrate; however, it had an extremely favorable response current to ascorbic acid (AA). Based on the above principle, the target CA15-3-triggered immunoassay enriched ALP-catalyzed AAP produces a large amount of AA, resulting in a significant change in the system current signal, thereby realizing the highly sensitive detection of CA15-3. Under the optimal AAP substrate concentration and ALP catalysis time, the Co-NC-SPCE-based electrochemical immunoassay demonstrated a good DPV current for CA15-3 in the assay interval of 1.0 mU/mL to 10,000 mU/mL, with a calculated limit of detection of 0.38 mU/mL. Since Co-NC-SPCE has an excellent DPV current response to AA and employs split-type scheme, the constructed electrochemical immunoassay has the merits of high preciseness and anti-interference, and its clinical diagnostic results are comparable to those of commercial kits.

Squamoid eccrine ductal carcinoma: clinical, histological and immunohistochemical features.

Squamoid eccrine ductal carcinoma (SEDC) is a cutaneous adnexal malignancy that is histologically challenging to distinguish from squamous cell carcinoma. We report three cases of this rare entity and review the present literature regarding clinical, histological, and immunohistochemical features. Patients presented with a single nodule or plaque lesion on their back and temple. The shave biopsies for Patient A and C were interpreted as SEDC. Patient B's initial shave biopsy was interpreted as probable surface of squamous cell carcinoma, and subsequent excision revealed SEDC. Ductal differentiation was confirmed by positive expression of epithelial membrane antigen and carcinoembryonic antigen immunostains in all three patients. Review of the 67 previously reported cases emphasizes the importance of diagnosing SEDC accurately and promptly given its potential for distant metastasis and mortality. Perineural or lymphatic invasion is associated with higher rate of recurrence or metastasis. There should be high pathologic suspicion for SEDC in an elderly patient presenting with a palpable lesion, even if located outside of the head and neck area, particularly when there is suggestion of ductal differentiation in a sample of a squamous neoplasm.

Dual-potential electrochemiluminescence of single luminophore for detection of biomarker based on black phosphorus quantum dots as co-reactant.

Simultaneous cathodic and anodic electrochemiluminescence (ECL) emissions of needle-like nanostructures of Ru(bpy)32+ (RuNDs) as the only luminophore are reported based on different co-reactants. Cathodic ECL was attained from RuNDs/K2S2O8 system, while anodic ECL was achieved from RuNDs/black phosphorus quantum dots (BPQDs) system. Ferrocene attached to the hairpin DNA could quench the cathodic and anodic ECL simultaneously. Subsequently, the ECL signals recovered in the presence of tumor marker mucin 1 (MUC1), which made it possible to quantitatively detect MUC1. The variation of ECL signal was related linearly to the concentrations of MUC1 in the range 20 pg mL-1 to 10 ng mL-1, and the detection limits were calculated to 2.5 pg mL-1 (anodic system, 3σ) and 6.2 pg mL-1 (cathodic system, 3σ), respectively. The recoveries were 97.0%, 105%, and 95.2% obtained from three human serum samples, and the relative standard deviation (RSD) is 5.3%. As a proof of concept, this work realized simultaneous ECL emission of  a single luminophore, which initiates a new thought in biomarker ECL detection beyond the traditional ones. Simultaneous cathodic and anodic ECL emissions of RuNDs were reported based on different co-reactants. Ferrocene could quench the ECL emission in the cathode and the anode simultaneously. Thus, an aptasensor was constructed based on the variation of ECL intensity. As a proof of concept, this work realized simultaneous ECL emission of a single luminophore, which initiates a new thought in biomarker ECL detection beyond the traditional ones by avoiding the false positive signals.

Annual variation rate of KL-6 for predicting acute exacerbation in patients with rheumatoid arthritis-associated interstitial lung disease.

OBJECTIVES: This study evaluated the prognostic factors for acute exacerbation (AE), including sequential changes in Krebs von den Lungen-6 (KL-6) levels, in rheumatoid arthritis-associated interstitial lung disease (RA-ILD) patients. METHODS: This was a retrospective observational study. We reviewed 125 patients diagnosed with RA-ILD between 2010 and 2019. We defined ΔKL-6 as the annual variation rate of KL-6 one visit before AE onset (or the last visit). The Cox regression analysis was used for evaluating significant variables associated with AE. We analysed the overall survival and respiratory-related death-free survival. RESULTS: Thirty-three patients (26.4%) developed AE during the observation period. The univariate analysis revealed that KL-6 levels at RA-ILD diagnosis [hazard ratio (HR), 1.11; 95% confidence interval (CI), 1.05-1.15; p < .01) and ΔKL-6 (HR: 3.69; 95% CI: -1.36 to 7.96; p = .01] were significantly associated with AE. ΔKL-6 was an independent prognostic factor for AE in the multivariate analysis (HR: 3.37; 95% CI: -1.16 to 8.87; p = .03). Patients with AE had a significantly higher overall mortality rate (p = .02) and respiratory-related mortality rate (p < .01) than those without AE. CONCLUSION: ΔKL-6 can be a prognostic marker for detecting AE in RA-ILD patients.

Dual-Probe Approach for Mass Spectrometric Quantification of MUC1-Specific Terminal Gal/GalNAc In Situ.

Protein glycosylation is a prevalent post-translational modification that mediates a variety of cellular processes. For membrane proteins, glycosylation at their terminal motif is usually more functional. Among the various glycosylation types found in membrane proteins, O-glycosylation is the most common and is closely correlated with a variety of cancer types, including breast cancer. Slightly aberrant expression of certain O-glycans can significantly affect cancer progression, especially at the cancer-related membrane protein level. To collect biological information on protein-specific glycosylation and further explore clinical applications, quantitative detection of glycosylation is essential. However, few assays have been reported for the in situ detection of protein-specific glycosylation to date. Herein, we developed a dual-probe approach for mass spectrometric quantification of protein-specific glycosylation using the terminal galactose/N-acetylgalactosamine (Gal/GalNAc) of MUC1 as a model. The dual-probe (i.e., protein probe and glycan probe) system was first designed and built. The protein probe contained an aptamer for MUC1 protein recognition and a capture DNA sequence. Correspondingly, the glycan probe had a DNA sequence complementary to that of the capture DNA, a substrate peptide containing a reporter peptide, and a tryptic cleavage site, and could be covalently linked with the terminal Gal/GalNAc. Exonuclease III enabled recycling of the hybridization-dehybridization process in a restricted space. Finally, the reporter peptide was tryptically released and quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The mass response of the reporter peptide represented the amount of MUC1-specific terminal Gal/GalNAc. This dual-probe approach was applied for in situ detection of MUC1-specific terminal Gal/GalNAc in three human breast cancer cell lines and 32 pairs of matched breast cancer tissue samples. The relationship between MUC1-specific terminal Gal/GalNAc expression and breast cancer diagnosis/prognosis was also assessed.

A SERS-colorimetric dual-mode aptasensor for the detection of cancer biomarker MUC1.

Human mucin-1 (MUC1) has attracted considerable attention owing to its overexpression in diverse malignancies. Here, for the rapid and efficient detection of MUC1, we present a SERS-colorimetric dual-mode aptasensor, by integrating SERS probes with magnetic separation, which has several distinctive advantages. Using such a dual-mode aptasensor, the colorimetric functionality is distinguishable by the naked eye, providing a fast and straightforward screening ability for the detection of MUC1. Moreover, SERS-based detection greatly improves the detection sensitivity, reaching a limit of detection of 0.1 U/mL. In addition, the combination of SERS and colorimetric method holds the advantages of these two techniques and thereby increases the reliability and efficiency of MUC1 detection. On the one hand, the magnetic nanobeads functionalized with MUC1-specific aptamer were utilized as an efficient capturing substrate for separating MUC1 from biological complex medium. On the other hand, the gold-silver core-shell nanoparticles modified with Raman reporters and the complementary sequences of MUC1 were used as the signal indicator, which could simultaneously report the SERS signal and colorimetric change. This strategy can achieve a good detection range and realize MUC1 analysis in real patients' samples. Thus, we anticipate that this kind of aptasensor would provide promising potential applications in the diagnosis and prognosis of cancers. Graphical abstract.

Nuclear staining of claudin-18 is a new immunohistochemical marker for diagnosing intramucosal well-differentiated gastric adenocarcinoma.

Diagnosis of gastric adenocarcinoma using small biopsy samples is occasionally difficult. Various markers have been employed for improving the diagnostic accuracy, but there remains room for improvement. A total of 129 endoscopically biopsied samples were studied, consisting of 104 intramucosal tubular adenocarcinomas, 24 non-cancerous lesions and one cancer sample originally suspected of non-cancer but revised as cancer after immunostaining. We evaluated the association between histopathology and immunohistochemical expression of MUC1, HER2, p53, CEA, E-cadherin, ß-catenin and claudin-18. Regarding ß-catenin and claudin-18, not only membranous expression (ß-catenin(M) and claudin-18(M)) but also nuclear expression (ß-catenin(N) and claudin-18(N)) were analyzed. When subtyped with mucin core protein expression, the gastric-type cancers dominantly expressed claudin-18(M), while claudin-18(N) was significantly encountered in intestinal- and mixed-types. Expression of MUC1 (P = 0.0010), HER2 (P = 0.0173), p53 (P = 0.0002), CEA (P = 0.0019) and claudin-18(N) (P < 0.0001) revealed significant correlation with gastric cancers. Negative correlation of claudin-18(M) (P = 0.0125) was also noted. MUC1 and p53 were negative in non-cancer lesions. The non-cancer group exceptionally expressed HER2 and ß-catenin(N). Membranous expression of E-cadherin was consistent in both groups. Logistic regression analysis showed that MUC1 (P = 0.0086), p53 (P = 0.0031), claudin-18(M) (P = 0.0158) and claudin-18(N) (P = 0.0190) were independently associated with gastric cancers. Nuclear expression of claudin-18 should be the novel diagnostic marker for gastric cancer.

Electrochemiluminescence Enhanced by Restriction of Intramolecular Motions (RIM): Tetraphenylethylene Microcrystals as a Novel Emitter for Mucin 1 Detection.

Apart from the reported energy transfer mechanism of aggregation-induced electrochemiluminescence (AI-ECL) enhancement, a new strategy named restriction of intramolecular motions-driven ECL (RIM-ECL) enhancement is first proposed based on the phenomenon of a very strong electrochemiluminescence observed on the hexagonal tetraphenylethylene microcrystals (TPE MCs) in aqueous solution. Compared to TPE in molecule-isolation state with faint ECL, TPE in aggregate state (TPE MCs) showed a significantly enhanced ECL that was due to the restriction of intramolecular motions (RIM). Inspired by the unique luminescence characteristic of TPE MCs, we integrated the novel ECL emitter of TPE MCs and target-activated bipedal DNA walker together to fabricate a sensitive "off-on" ECL biosensor for Mucin 1 (MUC1) assay, which exhibited desirable linear response for a concentration scope from 1 fg/mL to 1 ng/mL with a low detection limit of 0.29 fg/mL. The RIM enhanced ECL demonstrated by the TPE MCs provides a new chapter in the exploration of aggregated organic emitters for further applications.

Programmed Dual-Functional DNA Tweezer for Simultaneous and Recognizable Fluorescence Detection of microRNA and Protein.

A programmed dual-functional DNA tweezer (DFDT) as a signaling molecule is reported for the simultaneous and recognizable fluorescence detection of microRNA 21 (miRNA 21) and mucin 1 (MUC1). This unique DFDT is assembled from two Au-NP-attached central strands (C1 and C2) and an arm strand (A) dually ended by fluorophores Cy3 and Cy5, which are spatially separated from Au NP in the originally opened state. Through the competitive affinity interaction between targets and their complementary and aptamer sequences tethered in two recognition strands (R1 and R2), miRNA 21 and MUC1 are respectively converted into two dependently displaced fuel strands (F1 and F2). The next hybridization with two pairs of unpaired segments overhung in open DFDT leads to its conformational closure, resulting in the approach of Cy3 and Cy5 to Au NP. On the basis of the nanometal surface energy transfer scheme, the fluorescence emission of Cy3 or Cy5 is cooperatively quenched by Au NPs attached in C1 and C2. The significant variation of fluorescence intensity enables one-step, cost-effective, and specific quantization of miRNA 21 and MUC1 with high sensitivity down to 32 fM and 2.6 fg·mL-1 (8.5 pM), respectively. The novel DFDT-based assay route of multiplex analytes is promising and has the potential for rapid and reliable diagnosis and treatment of cancer-related diseases.

Electrochemical Aptasensor for Ultralow Fouling Cancer Cell Quantification in Complex Biological Media Based on Designed Branched Peptides.

The rapid, convenient, and selective assaying of clinical targets directly in complex biological media brings with it the potential to revolutionize diagnostics. One major hurdle to impact is retention of selectivity and a tight control of nonspecific surface interactions or biofouling. We report herein, the construction of an antifouling interface through the covalent attachment of designed branched zwitterionic peptides onto electrodeposited polyaniline film. The antifouling capability of the designed branched peptide significantly outperforms that of the commonly used PEG and linear peptides. The interfaces modified with branched peptides are exceptionally effective in reducing a nonspecific protein and cell adsorption, as verified by electrochemical and fluorescent characterization. The derived sensors with mucin1 protein (MUC1) aptamer as the recognition element detect MUC1-positive MCF-7 breast cancer cells in human serum with high sensitivity and selectivity. The linear response range of the cytosensor for the MCF-7 cell is from 50 to 106 cells/mL, with a limit of detection as low as 20 cells/mL. More importantly, the assaying performances remain unchanged in human serum owing to the presence of branched antifouling peptide, indicating feasibility of the cytosensor for practical cancer cell quantification in complex samples.

Visual Electrofluorochromic Detection of Cancer Cell Surface Glycoprotein on a Closed Bipolar Electrode Chip.

This work reports an electrofluorochromic strategy on the basis of electric field control of fluorescent signal generation on bipolar electrodes (BPEs) for visualizing cancer cell surface glycoprotein (mucin 1). The device included two separate cells: anodic sensing cell and cathodic reporting cell, which were connected by a screen-printing electrode patterned on poly(ethylene terephthalate) (PET) membrane. In the sensing cell, anti-MUC1 antibody immobilized on a chitosan-multiwalled carbon nanotube (CS-MWCNT)-modified anodic BPE channel was used for capturing mucin-1 (MUC1) or MCF-7 cancer cells. Then ferrocene (Fc)-labeled mucin 1 aptamers were introduced through hybridization. Under an applied voltage, the ferrocene was oxidized and the electroactive molecules of 1,4-benzoquinone (BQ) in the cathodic reporting cell were reduced according to electroneutrality. This produced a strongly basic 1,4-benzoquinone anion radical (BQ•-), which turned on the fluorescence of pH-responsive fluorescent molecules of (2-(2-(4-hydroxystyryl)-6-methyl-4 H-pyran-4-ylidene)malononitrile) (SPM) coexisting in the cathode reporting cell for both spectrophotometric detection and imaging. This strategy allowed sensitive detection of MUC1 at a concentration down to 10 fM and was capable of detecting a minimum of three MCF-7 cells. Furthermore, the amount of MUC1 on MCF-7 cells was calculated to be 6.02 × 104 molecules/cell. Our strategy also had the advantages of high temporal and spatial resolution, short response time, and high luminous contrast and is of great significance for human health and the promotion of life science development.