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Timely identification of cancers is pivotal in optimizing treatment efficacy and reducing their widespread impact. This study introduces a novel biosensor for the sensitive electrochemical detection of cancer cells overexpressing mucin 1 (MUC1), a well-established model for breast cancer. The sensor substrate comprises gold columnar nanostructures obtained through glancing angle deposition (GLAD) of copper nanostructures, subsequently replaced by gold via a facile galvanic replacement process. Functionalizing these gold nanostructures with aptamers targeting the MUC1 glycoproteins, a prominent cancer biomarker, enables specific recognition of MCF-7 breast cancer cells. The proposed electrochemical sensing platform offers several advantages, including high selectivity, a wide linear range of detection, a low detection limit of 30 cells per mL, and long-term stability, rendering this sensor highly desirable for definitive breast cancer diagnosis. [ABSTRACT FROM AUTHOR]

Lung cancer is one of the deadliest cancers worldwide due to the inability of existing methods for early diagnosis. Tumor-derived exosomes are nano-scale vesicles released from tumor cells to the extracellular environment, and their investigation can be very useful in both biomarkers for early cancer screening and treatment assessment. This research detected the exosomes via an ultrasensitive electrochemical biosensor containing gold nano-islands (Au-NIs) structures. This way, a high surface-area-to-volume ratio of nanostructures was embellished on the FTO electrodes to increase the chance of immobilizing the CD-151 antibody. In this way, a layer of gold was first deposited on the electrode by physical vapor deposition (PVD), followed by thermal annealing to construct primary gold seeds on the surface of the electrode. Then, gold seeds were grown by electrochemical deposition through gold salt. The cell-derived exosomes were successfully immobilized on the FTO electrode through the CD-151 antibody, and cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) methods were used in this research. In the CV method, the change in the current passing through the working electrode is measured so that the connection of exosomes causes the current to decrease. In the EIS method, surface resistance changes were investigated so that the binding of exosomes increased the surface resistance. Various concentrations of exosomes in both cell culture and blood serum samples were measured to test the sensitivity of the biosensor, which makes our biosensor capable of detecting 20 exosomes per milliliter. [ABSTRACT FROM AUTHOR]

A stable and sensitive non-enzymatic glucose sensor is proposed based on the hybrid thin films of copper on acetanilide/ITO-PET. The electrode was fabricated through a two-step synthesis process including electrochemical deposition of acetanilide on ITO-PET, subsequent by physical vapor deposition of a copper film. The electron microscopy images showed the formation of a porous structure on the ITO-PET sheet. Such modified electrode presents a high sensitivity of 59.95μAmM-1cm-2 with a low limit of detection of 1.501μM. This glucose sensor exhibits a range of linear response between 2 to 12mM. In addition, it includes a variety of advantages as high flexibility, the possibility for scale-up production, low material consumption, low cost, excellent reproducibility, high selectivity, good sensitivity and short response time. Finally, the glucose determination of different human blood serums indicates that the deviation of this sensor from the clinical measurements is less than 5%. [ABSTRACT FROM AUTHOR]

• We have produced porous Cu nanostructures by glancing angle deposition. • The Cu nanostructures deposited on FTO provide a sensitive glucose sensor. • Impressive electrochemical responses from the electrode were measured. • A high glucose detection sensitivity of 1862 μAcm−2 mM−1 was obtained. • The fabrication method proposes excellent reproducibility and selectivity. In this work, we have proposed a proper method to fabricate porous Cu nanostructured electrodes for non-enzymatic glucose detection. The glancing angle deposition (GLAD) has been used to produce Cu nanostructures on the FTO substrates. To optimize the sensing performance of the electrode, the effects of vapor deposition angle and azimuthal substrate rotation speed have been investigated. As a result, the superior electrocatalitic activity is obtained under the deposition angle of θ = 82° and the substrate rotation speed of φ ̇ = 20 rpm, respectively. By controlling the GLAD deposition parameters, an excellent sensing performance against glucose with a high sensitivity of 1862 μAcm−2 mM−1, a low detection limit of 0.048 μM and two wide linear ranges of detection of 10 μM–2 mM and 2–8 mM have been achieved at the applied potential of 0.5 V. Considering the high selectivity, excellent reproducibility and accurate measuring of the glucose levels in human serums, the proposed Cu-based sensor has a remarkable potential for large-scale production as a non-enzymatic glucometer. [ABSTRACT FROM AUTHOR]

The development of an electrochemical aptasensor for the detection of CA125 as an ovarian cancer biomarker using gold nanostructures (GNs) modified electrodes is reported. The GNs were deposited on the surface of fluorine-doped tin oxide electrodes using a simple electrochemical method and the effects of pH and surfactant concentration on the topography and electrochemical properties of the resulting GNs modified electrodes were investigated. The electrodes were characterized using field-emission scanning electron microscopy and X-ray diffraction, cyclic voltammetry, and electrochemical impedance spectroscopy. The best electrode, in terms of the uniformity of the deposited GNs and the increase in electroactive surface area, was used for development of an aptasensor for CA125 tumor marker detection in human serum. Signal amplification was done by using aptamer-conjugated gold nanorods resulting in the detection limit of 2.6 U/ml and a linear range of 10 to 800 U/ml. The results showed that without the need for expensive antibodies, the developed aptasensor could specifically measure the clinically relevant concentrations of the tumor marker in human serum., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)