Ultrasensitive Electrochemical Detection of cancer-Related Point Mutations Based on Surface-Initiated Three-Dimensionally Self-Assembled DNA Nanostructures from Only Two Palindromic Probes

Abstract

Sensitive and selective detection of proto-oncogenes, especially recognition of point mutation, is of great importance in cancer diagnosis. Here, a ligation-mediated technique is demonstrated for the construction of an intertwined three-dimensional DNA nanosheet (3D SDN) on an electrode surface from only two palindromic hairpin probes (HP1 and HP2), creating a powerful electrochemical biosensor (E-biosensor) for the detection of the p53 gene. First, a capturing probe (CP) is immobilized on an electrode surface via Au−S chemistry, forming an electrochemical sensing interface. In the presence of the target p53 (T), the triggering probe is covalently linked to CP by a ligase. Moreover, target hybridization/ligation/dehybridization process is repeated, amplifying the target hybridization event and increasing the content of surface-confined triggering fragments. As a result, HP1 is opened and in turn interacts with HP2, forming intertwined 3D SDN where HP1 and HP2 are alternately arranged in parallel. Common hybridization and interaction between palindromic fragments are responsible for the assembly in the horizontal and vertical directions, respectively. An electrochemical indicator, methylene blue (MB), can be inserted into 3D SDN, generating a strong electrochemical signal. Utilizing the 3D SDN-based E-biosensor, the target DNA is detected down to 3 fM with a linear response range from 10 fM to 10 nM. Single point mutations are reliably identified even in fetal bovine serum and cellular homogenate. Because of the several advantages of simple design, good universality, inexpensive instrumentation, high assay specificity, and sensitivity, the 3D SDN-based E-biosensor is expected to provide a potential platform for screening point mutation required by early clinical diagnostics and medical research.

Versatile Photoelectrochemical Biosensing for Hg2+ and Aflatoxin B1 Based on Enhanced Photocurrent of AgInS2 Quantum Dot–DNA Nanowires Sensitizing NPC–ZnO Nanopolyhedra

“…As a result, this may cause DNA nanowires to intercross, allowing multiple strands of nanowires to form bundles and may increase the width of DNA nanowires . It is also worth noting that the width of DNA nanowires in the reported AFM and TEM images is consistent with our results. , It can be seen from Figure B that the average length of the nanowire is 800 nm ± 100 nm, and the height is 2 nm, which is consistent with the length of the nanowire in the TEM image. In order to verify the successful formation of AIS QD–DNA nanowires, AFM image analysis was carried out (Figure C).…”

Nucleic acid isothermal amplification-based soft nanoarchitectonics as an emerging electrochemical biosensing platform

“…The targeted trigger HCR reaction completed on the electrode generates a long double-stranded DNA, which could bind large number of electrochemical tags (such as methylene blue MB labelled DNA strands, RuHex, or hemin/G-quadruplex 27 ) on it. This enables enhanced signal-amplified electrochemical sensing for various targets, including micro RNA21, 28 exosomal microRNA, 29 and p53DNA 30 at fM or even aM level. Different from the traditional architecture of the hairpin capture probe and the generated long linear HCR product on the sensing electrode, some novel architecture strategies have been developed.…”

“…Then, upon the addition of two palindromic probes, intertwined 3D SDN formed and inserted with methylene blue as an electrochemical indicator, which generated a strong electrochemical signal. 30 Miao's recent work designed a three-way junction structure-based dumbbell HCR on the electrode. The dumbbell HCR structure not only keeps the high efficacy of HCR but also shows the tight conformation of the HCR product, which is helpful in shortening the distance between electrochemical species and the electrode interface for enhancement of the electrochemical response, thus obtaining an improved LOD of microRNA to as low as 7.3 aM.…”

Detection of the p53 Gene Mutation Using an Ultra-sensitive and Highly Selective Electrochemical DNA Biosensor

“…The p53 mutation is one of the most frequent genetic alterations in human cancer, and more than 50% of cancers are related to this mutation [5]. When the p53 gene mutates it adopts oncogenic activities that initiate and promote tumorigenesis, progression, metastasis, and drug resistance [6]. In addition, this gene mutation allows diagnosis in early stages, prognostic and risk of recurrence evaluations, and determining the response of tumors to therapy [7,8].…”

“…In addition, this gene mutation allows diagnosis in early stages, prognostic and risk of recurrence evaluations, and determining the response of tumors to therapy [7,8]. Therefore, highly sensitive and reliable detection of the mutant p53 gene is essential for detecting, preventing, and treating cancer [6].…”