Investigating the Electric Field Lysis of Exosomes Immobilized on the Screen-Printed Electrode and Electrochemical Sensing of the Lysed-Exosome-Derived Protein

Abstract

It is important to isolate exosomes (<150 nm) from biofluid for diagnosis or prognosis purposes, followed by sensing of exosomal proteins. In the present work, exosomes are isolated from human serum by immobilizing on a Screen-Printed Electrode (SPE) followed by electric field lysis and electrochemical impedance spectroscopy (EIS)-based sensing of relevant exosomal proteins (HSP70 and HER2). Upon immobilization of exosomes on the surface, the role of different electrical signals (sinusoidal and square wave) in the lysis of exosomes was studied by varying the frequency and voltage. HSP70 was used for EIS to determine the optimal voltage and frequency for lysing the exosomes. It was observed that the low frequencies and, specifically, sinusoidal signals are ideal for lysing exosomes as compared to square signals. The relative quantity of HSP70 obtained by lysing with different voltages (sinusoidal waveform) was compared using Western blotting. After electric field lysis of the exosome with an optimized signal, HER2, a breast cancer biomarker, was detected successfully from serum by EIS. In the proposed technique, 3.5 × 108 exosomes/mL were isolated from serum. With the limit of detection of 10 pg, the designed cell showed a linear detection of HER2 from 0.1 ng to 1 µg. It was observed from the results that the electric field lysis of exosomes not only plays a significant role in releasing the cargo protein but also improves the sensing of surface proteins associated with exosomes.

Advancements and Clinical Significance of Breast Cancer Exosome Detection

“…The linear detection range of HER2 was found to be 0.1 ng -1 µg with a detection limit of 10 pg. In this technique, electric field-induced lysis released proteins from exosomes, thereby enhancing the sensitivity of the sensing device [29].…”

Review—Prospects in Cancer Diagnosis: Exosome-Chip for Liquid Biopsy

“…115,116 Further, the incorporation of nanomaterials for developing electrochemical ECs showed enhanced performance due to the high loading of antibodies (anti-CD63) specific to exosomes. 117 The traditional EC developed for electrochemical nanosensing of exosomes (or antigens) provides limited sensitivities and limit-of-detection owing to the one and twodimensional geometries of the electrodes with limited reactive surfaces. 118 It has been realized that nanostructuring of sensor surfaces alone is inadequate to detect low target concentration down to the femtomolar level.…”

Extraction-free, one-pot CRISPR/Cas12a detection of microRNAs directly from extracellular vesicles

“…Chemical lysis of EVs using chaotropic salts is commonly used in bench-top protocols and has been integrated on chips, 6 however, it requires multiple steps for RNA extraction and the removal of interfering molecules, which is time-consuming. Besides, physical lysis methods such as acoustic wave lysis 7 and electric field lysis 8 have also been deployed in the EV lysis, but they require specialized devices and increase assay complexity. In contrast, thermolysis is capable of lysing lipid membranes by a simple and fast heating process without introducing potential amplification inhibitors or requiring complex instruments, [9][10][11] thus, it can remarkably simplify the detection of miRNAs in EVs.…”