Electrochemical DNA-based Biosensor Research Articles

Development of an advanced DNA biosensor for pathogenic Vibrio cholerae detection in real sample

Due to the epidemics of emerging microbial diseases worldwide, the accurate and rapid quantification of pathogenic bacteria is extremely critical. In this work, a highly sensitive DNA-based electrochemical biosensor has been developed to detect Vibrio cholerae using gold nanocube and 3-aminopropyltriethoxysilane (APTES) modified glassy carbon electrode (GCE) with DNA carrier matrix. Electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) experiments were performed to interrogate the proposed sensor at each stage of preparation. The biosensor has demonstrated high sensitivity with a wide linear response range to target DNA from 10−8 to 10−14 (R2= 0.992) and 10−14 to 10−27 molL−1 (R2= 0.993) with a limit of detection (LOD) value of 7.41 × 10−30 molL−1 (S/N = 5). The biosensor also exhibits a selective detection behavior in bacterial cultures that belong to the same and distant genera. Moreover, the proposed sensor can be used for six consecutive DNA assays with a repeatability relative standard deviations (RSD) value of 5% (n = 5). Besides, the DNA biosensor shows excellent recovery for detecting V. cholerae in poultry feces, indicating that the designed biosensor could become a powerful tool for pathogenic microorganisms screening in clinical diagnostics, food safety, and environmental monitoring.

Emerging DNA-based multifunctional nano-biomaterials towards electrochemical sensing applications.

DNA is known to be ubiquitous in nature as it is the controlling unit for genetic information storage in most living organisms. Lately, there has been a surge in studies relating to the use of DNA as a biomaterial for various biomedical applications such as biosensing, therapeutics, and drug delivery. The role of DNA as a bioreceptor in biosensors has been known for a long time. DNA-based biosensors are gradually evolving into highly sophisticated and sensitive molecular devices. The current realization of DNA-based biosensors embraces the unique structural and functional properties of DNA in the form of a biopolymer. The interesting properties of DNA, such as self-assembly, programmability, catalytic activity, dynamic behavior, and precise molecular recognition, have led to the emergence of innovative DNA assembly based electrochemical biosensors. This review article aims to cover the recent progress in the field of DNA-based electrochemical (EC) biosensors. It commences with an introduction to electrochemical biosensors and elucidates the advantages of integrating DNA-based materials into them. Besides this, we discuss the principles of EC biosensors based on different types of DNA-based materials. The article concludes by highlighting the outlook and importance of this interesting field for biomedical developments.

Label-Free DNA Biosensor Using Modified Reduced Graphene Oxide Platform as a DNA Methylation Assay.

This work reports the use of modified reduced graphene oxide (rGO) as a platform for a label-free DNA-based electrochemical biosensor as a possible diagnostic tool for a DNA methylation assay. The biosensor sensitivity was enhanced by variously modified rGO. The rGO decorated with three nanoparticles (NPs)—gold (AuNPs), silver (AgNPs), and copper (CuNPs)—was implemented to increase the electrode surface area. Subsequently, the thiolated DNA probe (single-stranded DNA, ssDNA−1) was hybridized with the target DNA sequence (ssDNA-2). After the hybridization, the double-stranded DNA (dsDNA) was methylated by M.SssI methyltransferase (MTase) and then digested via a HpaII endonuclease specific site sequence of CpG (5′-CCGG-3′) islands. For monitoring the MTase activity, differential pulse voltammetry (DPV) was used, whereas the best results were obtained by rGO-AuNPs. This assay is rapid, cost-effective, sensitive, selective, highly specific, and displays a low limit of detection (LOD) of 0.06 U·mL−1. Lastly, this study was enriched with the real serum sample, where a 0.19 U·mL−1 LOD was achieved. Moreover, the developed biosensor offers excellent potential in future applications in clinical diagnostics, as this approach can be used in the design of other biosensors.

Evaluation of antioxidant activity of chlorogenic acids and coffee extracts by an electrochemical DNA-based biosensor

Sensitivity of dsDNA structure towards OH radicals as the pro-oxidants has been utilized as the detection principle of an analytical procedure applied for the first time to the evaluation of antioxidant activity (AOA) of 6 chlorogenic acids (CGAs) and extracts of 10 coffees. A nanostructured electrochemical DNA-based biosensor was prepared using a commercial electrode assembly and treated in the DNA cleavage agent formed by the Fenton type reaction. An addition of CGAs and aqueous coffee extracts significantly diminishes the degree of DNA degradation determined using cyclic voltammetry (CV) with the redox indicator [Fe(CN)6]3−/4−. The AOA decreases in order caffeic acid, CFA, >caffeoylquinic acids, CQAs, >dicaffeoylquinic acids, diCQAs, exhibiting the relative portion of survived DNA of about 71%, 70% and 69%, respectively, and of about 72% for C. robusta, Cherry, India (green bean) to 49% for Nescafé Espresso. Mechanisms of antioxidative properties are discussed.

Detection of Mycobacterial Mannose‐capped Lipoarabinomannan via Electrochemical Biosensor

Mycobacterium tuberculosis (M.tb) is one of the world’s most prevalent bacterial pathogens. However, Nontuberculous Mycobacterium (NTM) are less recognized than M.tb while remaining a pressing public health risk. Often, NTM lung disease is confused with that of a tubercle infection leading to unreliable diagnosis. Additionally, the time spent to fully diagnose a mycobacterial disease is extensive and dependent on the species growth rate due to the necessity of culturing for identification. Thus, designing a sensitive, electrochemical DNA‐based (E‐DNA) biosensor as a diagnostic tool for NTM would dramatically decrease the timeline of diagnosis and therefore could improve patient outcomes. In this work, we pursued detection of the cell envelope of NTM, which includes many complex glycolipids and glycopeptidolipids—many of which are believed to have immunopathogenic mechanisms. As mannose‐capped lipoarabinomannan (ManLAM) is one of the most prevalent of the glycolipids, we adapted it as a biomarker for the sensitive detection of NTM. An aptamer specific to ManLAM was incorporated into our E‐DNA biosensor, and exhibits significant current change under square wave voltammetric interrogation.

Detection of Ostreopsis cf. ovata in environmental samples using an electrochemical DNA-based biosensor

Ostreopsis cf. ovata is a benthic microalga distributed in tropical and temperate regions worldwide which produces palytoxins (PlTXs). Herein, an electrochemical biosensor for the detection of this toxic microalga is described. The detection strategy involves isothermal recombinase polymerase amplification (RPA) of the target using tailed primers and a sandwich hybridisation assay on maleimide-coated magnetic beads immobilised on electrode arrays. The biosensor attained a limit of detection of 9 pg/μL of O. cf. ovata DNA (which corresponds to ~640 cells/L), with no interferences from two non-target Ostreopsis species (O. cf. siamensis and O. fattorussoi). The biosensor was applied to the analysis of planktonic and benthic environmental samples. Electrochemical O. cf. ovata DNA quantifications demonstrated an excellent correlation with other molecular methods (qPCR and colorimetric assays) and allowed the construction of a predictive regression model to estimate O. cf. ovata cell abundances. This new technology offer great potential to improve research, monitoring and management of O. cf. ovata and harmful algal blooms.

Automating the design of structure‐switching aptamer biosensors

For both personalized medicine and academic research, there is pressing need for tools to enable the rapid interrogation of an array of biological targets associated with diseased states. Electrochemical, DNA‐based (E‐DNA) biosensors utilize the dynamic nature of nucleotide polymers to quantify the concentration of a specific peptide, substrate, or heavy‐metal species contained in a biological sample. A critical limitation of E‐DNA biosensors is the complexity associated with designing a nucleotide sequence that maximizes sensitivity while maintaining specificity. This dilemma is further complicated by the vast number of conformations that can exist for a given sequence. While great strides have been made in computationally predicting the folded structures that DNA and RNA‐based biosensors may assume, interpreting whether such predicted structures would be effective biosensors and using that knowledge to design functional E‐DNA biosensors ab initio remains challenging, suggesting the utility of an in silico approach to E‐DNA sensor design. We have created a program called Fealden, which automates the process of aptamer‐based biosensor generation. Fealden utilizes several programmatic paradigms to build an ideal E‐DNA biosensor sequence; the validity of this sequence is then assessed by assigning thermodynamic values and conformational distance metrics to each possible fold. Using these metrics, Fealden can provide the user with several candidates for an E‐DNA aptamer biosensor that are sensitive to the target of interest. Fealden has already been applied to optimize the detection of the antibiotic tobramycin with minimal human interaction. This work provides insights into applying an algorithmic approach to utilize the wide pool of existing aptamers as E‐DNA biosensors in practical applications spanning such diverse fields as food safety, environmental monitoring, and clinical diagnostics.Support or Funding InformationThis work is supported by internal grant funding from the Metropolitan State University of Denver.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Detection of Celiac Disease Autoantibodies with a Rapid and Noninvasive Diagnostic Biosensor

Celiac Disease (also known as gluten‐sensitive enteropathy and nontropical sprue) is estimated to affect between 0.5–1.0% of the general population of the United States (1.6 million to 3.3 million during 2017) with many of these cases being under‐diagnosed. Celiac Disease (CD) is the genetic hypersensitivity to ingested exogenous gluten. Subsequent exposure to gluten related proteins lead to the development of an autoimmune response, causing damage to the lining of the gastrointestinal tract. Due to increased inflammation, symptomatic individuals present with abdominal pain, diarrhea, nausea, and many other gastrointestinal complications. However, some individuals affected by CD are asymptomatic creating increased diagnostic error. An accurate diagnosis of CD remains challenging; current diagnostic procedures involve multi‐day serological screening, followed by invasive gastrointestinal biopsies of suspected lesions. Baring this in mind, there is a pressing need for a rapid, non‐invasive, and accurate detection method to diagnose individuals suffering from this disease. Our method is based on the known autoimmune interactions related to CD. Specifically, we observe the formation of a structured complex between a unique epitope—a chimera of tissue transglutaminase 2 and truncated gluten peptide—and the autoantibodies produced in response to the presence of gluten related proteins. Conducted within our research, we demonstrate a CD‐related diagnostic tool for early, accurate, and rapid disease identification of affected individuals. This tool is a electrochemical DNA‐based biosensor (E‐DNA) that relies on peptide epitopes acting as capture probes to detect levels of disease‐specific antibodies. This commonly used biosensor is utilized to detect small changes in electrical conductivity to determine whether or not a target molecule has been bound. In principle, this sensor design can be utilized for unprocessed finger‐lancet blood samples to provide a rapid digital readout, allowing for efficient and accurate diagnoses of CD affected patients.Support or Funding InformationThis work is supported by internal grant funding from the Metropolitan State University of Denver.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Toward multimarker and functional assays from crude cell lysates: controlling spacing and signal amplification in DNA-CT–based bioelectrochemical devices

Abstract DNA-based electrochemical biosensors that rely on charge transport through DNA (DNA-CT) to detect biomarkers of interest have shown great promise in proof-of-principle studies because of their specificity, sensitivity, and low cost. However, this approach has not translated successfully into real clinical applications. One significant barrier has been the need to measure biomarkers in unpurified, complex cell and tissue lysates, which is difficult with DNA-modified electrodes because of crowding and nonspecific adhesion of biomolecules to the surface. Here, we discuss recent achievements in the control of DNA monolayer formation and the amplification of DNA CT signals that help to facilitate the detection of meaningful biomarkers from unprocessed, clinically relevant lysate samples.

Amplified detection of single base mismatches with the competing-strand assay reveals complex kinetic and thermodynamic behavior of strand displacement at the electrode surface

Detection of single-base mismatches with respect to a probe strand has been a predominant pursuit in electrochemical biosensor efforts, due to links found between single nucleotide polymorphisms (SNPs) and the predisposition to various diseases. We report an osmium tetroxide bipyridine-based, thermally-controlled, competitive-strand electrochemical assay to allow amplified detection of single-base mismatches. Optimally designed competitive-strand displacement and hybridization temperature allows us to distinguish the single-mismatched-target from the fully complementary sequence with unambiguous, highly reproducible, robust signal differences of over 90%. Furthermore, we find a complex interplay between the position of the redox label, variations in strand displacement kinetics due to mismatches incorporated into the competitive strand, and alterations in the melting temperature of DNA duplexes tethered on the gold surface, when probed by square-wave voltammetry. These insights will apply to any surface-tethered DNA-based electrochemical biosensor, and can help with understanding complex phenomena involved in these types of assays.

Interaction of DNA and mononucleotides with theophylline investigated using electrochemical biosensors and biosensing

The understanding of DNA-drug interaction mechanism is among the important aspects of biological studies for drug design, discovery and pharmaceutical development processes. Published rather detailed FTIR and UV–visible spectroscopic studies on the interactions of theophylline, theobromine and caffeine with calf thymus DNA have shown effective binding of these methylxanthine derivatives to DNA and RNA involving H-bonds. However, to our knowledge, there is no such investigation using electrochemical approach. As a novelty of the study, in this paper the bioelectrochemical approach has been chosen for the investigation of an interaction of low molecular salmon sperm dsDNA, ssDNA and mononucleotides with theophylline (TP) in aqueous phosphate buffered medium using DNA-based electrochemical biosensors and biosensing in solution phase. Exploitation of the electrochemical approach via changes in square wave voltammetric responses of deoxyguanosine (dGuo) and deoxyadenosine (dAdo) provided a new indication on preferential association of TP with dGuo in the case of double helical dsDNA structure which was not reported previously. Moreover, an attachment of TP molecules outside DNA was found in the presence of high concentration of 3.3 × 10−4 M TP in solution which diminishes the electron transfer and leads to the difficulties in quantitative evaluation of the TP and dGuo voltammetric responses. The changes in UV–vis and FTIR spectra obtained in the same medium confirmed the association interaction of TP with both nucleobases. Utilizing the model and the published energies of hydrogen bonding stabilization, the formation of a DNA-TP complex was predicted through the intermolecular H-bonds between TP and the NH-CO moiety of guanine and the N-NH2 moiety of adenine.

Sensitive electrochemical DNA-based biosensors for the determination of Ag+ and Hg2+ ions and their application in analysis of amalgam filling

In the present paper, we used single-stranded poly-T (100% thymine bases) and poly-C (100% cytosine bases) nucleic acids as DNA probes for selective and sensitive individual electrochemical determination of Hg2+ and Ag+, respectively, on the multi-walled carbon nanotube paste electrodes (MWCNTPEs) using [Fe(CN)6]3−/4− as electroactive labels. In the presence of Hg2+ and Ag+, the probe–Hg2+/Ag+ interactions through T–Hg2+–T and C–Ag+–C complexes formation could cause the formation of a unimolecular hybridized probe. This structure of probe led to its partial depletion from electrode surface and facilitation of electron transfer between [Fe(CN)6]3−/4− redox couple and electrode surface, resulting in the enhanced differential pulse voltammetry (DPV) oxidation current of [Fe(CN)6]3−/4− at the probe-modified electrode surface. We applied the difference in the oxidation peak currents of [Fe(CN)6]3−/4− before and after Hg2+/Ag+–DNA probe bonding (∆I) for electrochemical determination of these heavy metal ions. Detection limits were 8.0 × 10−12 M and 1.0 × 10−11 M for Hg2+ and Ag+ ions determination, respectively. The biosensors were utilized to determine the weight percent of toxic metals, i.e., silver and mercury in dental amalgam filling composition. The results of their practical applicability in analysis of the amalgam sample were satisfactory.

Electrochemical DNA biosensors: a review

PurposeThis review aims to focus on recent reported research work on the construction and function of different electrochemical DNA biosensors. It also describes different sensing materials, chemistries of immobilization probes, conditions of hybridization and principles of transducing and amplification strategies.Design/methodology/approachThe human disease-related mutated genes or DNA sequence detection at low cost can be verified by the electrochemical-based biosensor. A range of different chemistries is used by the DNA-based electrochemical biosensors, out of which the interactions of nanoscale material with recognition layer and a solid electrode surface are most interesting. A diversity of advancements has been made in the field of electrochemical detection.FindingsSome important aspects are also highlighted in this review, which can contribute in the creation of successful biosensing devices in the future.Originality/valueThis paper provides an updated review of construction and sensing technologies in the field of biosensing.

Application of DNA-based electrochemical biosensor in rapid detection of Escherichia coli exist in licorice decoction

A new method for detection of Escherichia coli exist in licorice decoction was developed by using DNA-based electrochemical biosensor. The thiolated capture probe was immobilized on a gold electrode at first. Then the aptamer for Escherichia coli was combined with the capture probe by hybridization. Due to the stronger interaction between the aptamer and the E. coli, the aptamer can dissociate from the capture probe in the presence of E. coli in licorice decoction. The biotinylated detection probe was hybridized with the single-strand capture probe. As a result, the electrochemical response to Escherichia coli can be measured by using differential pulse voltammetric in the presence of α-naphthyl phosphate. The plot of peak current vs. the logarithm of concentration in the range from 2.7×10² to 2.7×10⁸ CFU·mL⁻¹ displayed a linear relationship with a detection limit of 50 CFU·mL⁻¹. The relative standard deviation of 3 successive scans was 2.5%，2.1%，4.6% for 2×10²，2×10⁴，2×106：⁶ CFU·mL⁻¹ E. coli, respectively. The proposed procedure showed better specificity to E. coli in comparison to Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis. In the detection of the real extractum glycyrrhizae, the results between the proposed strategy and the GB assay showed high degree of agreement, demonstrating the designed biosensor could be utilized as a powerful tool for microbial examination for traditional Chinese medicine.

Behaviour and detection of acridine-type DNA intercalators in urine using an electrochemical DNA-based biosensor with the protective polyvinyl alcohol membrane

The aim of this work is preparation and use of an electrochemical DNA-based biosensor with a textured surface for the investigation of dsDNA host-guest interactions with specific chemicals in a biological sample of complex matrix such as urine. Results obtained at the search and optimization of polymer protective films over the DNA recognition layer at a glassy carbon electrode show that a polyvinyl alcohol membrane is the effective barrier able to stabilize the biosensor response in urine. The detection of acridines using the square-wave voltammetric (SWV) scan in the cathodic direction has allowed overcoming a problem of the electrochemical interference of DNA bases and acridines at the direct anodic scan. Height of the well-separated SWV peak at around 0.00V to +0.10V (which corresponds to the reduction of the oxidation products of both of acridines) depends on the concentration of acridines. The peak potentials of acridines were shifted by about 0.10V to the negative potential values in the urine medium compared to phosphate buffer. Intercalation of acridine yellow and proflavine into dsDNA was confirmed both in phosphate buffer and in urine.

Design of an electrochemical DNA-based biosensor for selective determination of cadmium ions using a DNA hybridization indicator

A simple electrochemical DNA- based biosensor was designed for determination of Cd2+ using ethyl green (EG) as a DNA hybridization indicator on the surface of carbon paste electrode (CPE). The interaction of Cd2+ with double strand DNA (dsDNA) led to the destabilizing of dsDNA and the increase in the reduction peak currents of EG. The difference in the values of electrochemical responses of EG before and after DNA helix destabilization in the presence of Cd2+ (ΔI) was used for Cd2+ determination and was linearly related to the concentration of Cd2+ over the ranges of 1.0pM–1.0nM and 10.0nM–1.0μM. Detection limit was achieved as low as 0.3pM using simple and low cost working electrode and without applying any materials for modification of electrode or DNA. The proposed biosensor was utilized successfully to real sample analysis of Cd2+.

Assessment of CdS quantum dots effect on UV damage to DNA using a DNA/quantum dots structured electrochemical biosensor and DNA biosensing in solution

Oxidation stress induced by nanoparticles is considered to be the main mechanism of their toxicity. An evaluation of oxidative damage to DNA, one of the mostly endangered molecules, belongs to general approaches used in nanomaterials cytotoxicology. However, for spherical, biochemical and other reasons, they should be differences in nanoparticles behaviour using tests based on cells and pure nucleic acid substances. The goal of the work is to detect structural damage to isolated salmon sperm double stranded DNA at its exposure to UV-C radiation (254nm) in the presence of thiol-capped CdS quantum dots of various size and fluorescence intensity. An electrochemical DNA-based biosensor composed of a glassy carbon electrode with a layered structure of chemical modifiers dsDNA and CdS QDs was prepared and used for the voltammetric and impedimetric evaluation of a DNA portion survived after the irradiation. The cyclic voltammetric response of the redox indicator system hexacyanoferrate(III/II) and square wave voltammetric response of the guanine and adenine moieties were measured as analytical signals. The results were verified by experiments with irradiation of DNA in the solution phase followed by voltammetric measurement of immobilized survived portion of DNA (biosensing) and by conventional agarose gel electrophoresis. Experiments showed significant effect of the fluorescent active quantum dots on the degree of DNA degradation.

Immobilization free electrochemical biosensor for folate receptor in cancer cells based on terminal protection

The determination of folate receptor (FR) that over expressed in vast quantity of cancerous cells frequently is significant for the clinical diagnosis and treatment of cancers. Many DNA-based electrochemical biosensors have been developed for FR detection with high selectivity and sensitivity, but most of them need complicated immobilization of DNA on the electrode surface firstly, which is tedious and therefore results in the poor reproducibility. In this study, a simple, sensitive, and selective electrochemical FR biosensor in cancer cells has been proposed, which combines the advantages of the convenient immobilization-free homogeneous indium tin oxide (ITO)-based electrochemical detection strategy and the high selectivity of the terminal protection of small molecule linked DNA. The small molecule of folic acid (FA) and an electroactive molecule of ferrocence (Fc) were tethered to 3′- and 5′-end of an arbitrary single-stranded DNA (ssDNA), respectively, forming the FA-ssDNA-Fc complex. In the absence of the target FR, the FA-ssDNA-Fc was degraded by exonuclease I (Exo I) from 3′-end and produced a free Fc, diffusing freely to the ITO electrode surface and resulting in strong electrochemical signal. When the target FR was present, the FA-ssDNA-Fc was bound to FR through specific interaction with FA anchored at the 3′-end, effectively protecting the ssDNA strand from hydrolysis by Exo I. The FR-FA-ssDNA-Fc could not diffuse easily to the negatively charged ITO electrode surface due to the electrostatic repulsion between the DNA strand and the negatively charged ITO electrode, so electrochemical signal reduced. The decreased electrochemical signal has a linear relationship with the logarithm of FR concentration in range of 10fM to 10nM with a detection limit of 3.8fM (S/N=3). The proposed biosensor has been applied to detect FR in HeLa cancer cells, and the decreased electrochemical signal has a linear relationship with the logarithm of cell concentration ranging from 100–10000cell/mL. Compared with the traditional heterogeneous electrochemical FR biosensors, the proposed biosensor owns the merits of the simplicity and high specificity, presenting the great potential application in the area of early diagnosis of cancers.

A Simple DNA-based Electrochemical Biosensor for Highly Sensitive Detection of Ciprofloxacin Using Disposable Graphene.

In this work we exploited the electrostatic interaction of double stranded DNA (dsDNA) with drug components to construct a simple, but highly sensitive, DNA-electrochemical sensor for detecting ciprofloxacin. The following straightforward three-step procedure was performed to determine ciprofloxacin: (i) dsDNA-layer immobilization on the surface of the working graphene-modified screen-printed carbon electrode; (ii) dsDNA-ciprofloxacin interaction for 2 min; and (iii) electrochemical measurement using square-wave voltammetry. An increased oxidation of the guanine component was observed, at +1.0 V, as a result of the electrostatic interaction of positively charged ciprofloxacin with the negatively charged nucleic acid sugar phosphate. Based on the International Conference on Harmonization Guidelines, a linear relationship between the guanine oxidation peak and ciprofloxacin concentration (0.1 to 100 μM) was obtained with a detection limit of 0.1 μM. Our developed sensor is straightforward to construct and use, requiring no multi-step time-consuming preconditioning of electrodes. It is highly sensitive and selective in the detection of ciprofloxacin, and has the potential to be useful in the future fabrication of rapid and portable on-site food safety analysis devices.

Total antioxidant capacity of plant infusions: Assessment using electrochemical DNA-based biosensor and spectrophotometric methods

Nine plant infusions were assessed in terms of their polyphenolic compounds and antioxidant capacity properties by performing a “battery” of assays. Bioactive compounds (total phenolic and flavonoid content) were measured using spectrophotometric procedures and the total antioxidant capacity was determined by DPPH-RSA, FRAP and DNA-based biosensor against the reactive oxygen species: HO and H2O2. Although the optical methods are based on the donation of hydrogen or electrons between antioxidants and radicals, the DNA-based biosensor intends to simulate an in vivo assay by exposing DNA layer to biological ROS and antioxidants. In general, green and black tea showed higher polyphenolic content and antioxidant capacity evaluated by the described methods. All the analysed plant beverages showed to be a good source of bioactive compounds, particularly the green and black tea, peppermint and senna.