Reversible Chain Research Articles

Remote Catalytic C(sp3)-H Alkylation via Relayed Carbenoid Transfer upon Olefin Chain Walking.

Transition metal carbenes have emerged as versatile intermediates for various types of alkylations. While reactions of metal carbene species with alkenes have been extensively studied, most examples focus on cyclopropanation and allylic C-H insertion. Herein, we present the first example of a catalytic strategy for the carbene-involved regioselective remote C-H alkylation of internal olefins by synergistically combining two iridium-mediated reactivities of olefin chain walking and carbenoid migratory insertion. The present method, utilizing sulfoxonium ylides as a bench-stable robust carbene precursor, was found to be effective for a series of olefins tethered with alkyl chains, heteroatom substituents, and complex biorelevant moieties. Combined experimental and computational studies revealed that reversible iridium hydride-mediated olefin chain walking proceeds to lead to a terminal alkyl-Ir intermediate, which then forms a carbenoid species for the final migratory insertion, resulting in regioselective terminal-alkylated products.

Efficiency of reversible MCMC methods: elementary derivations and applications to composite methods

Abstract We review criteria for comparing the efficiency of Markov chain Monte Carlo (MCMC) methods with respect to the asymptotic variance of estimates of expectations of functions of state, and show how such criteria can justify ways of combining improvements to MCMC methods. We say that a chain on a finite state space with transition matrix P efficiency-dominates one with transition matrix Q if for every function of state it has lower (or equal) asymptotic variance. We give elementary proofs of some previous results regarding efficiency dominance, leading to a self-contained demonstration that a reversible chain with transition matrix P efficiency-dominates a reversible chain with transition matrix Q if and only if none of the eigenvalues of $Q-P$ are negative. This allows us to conclude that modifying a reversible MCMC method to improve its efficiency will also improve the efficiency of a method that randomly chooses either this or some other reversible method, and to conclude that improving the efficiency of a reversible update for one component of state (as in Gibbs sampling) will improve the overall efficiency of a reversible method that combines this and other updates. It also explains how antithetic MCMC can be more efficient than independent and identically distributed sampling. We also establish conditions that can guarantee that a method is not efficiency-dominated by any other method.

A Stochastic FRET Study on the Core Dimension of Polystyrene-block-Poly(Polyethylene Glycol Monomethyl Ether Acrylate) Micelles.

Polystyrene-b-poly(polyethylene glycol monomethyl ether acrylate) (PSt-b-PPEGA) copolymers featuring pyrene and perylene as the Förster resonance energy transfer (FRET) donor (denoted as D-BCP) and acceptor (denoted as A-BCP), respectively, were synthesized via the reversible addition and fragmentation chain transfer (RAFT) polymerization. These copolymers were then used to form DA-mixed micelles via a dialysis method. The micelles consisted of D-BCP (mole fraction fD = 0.04), A-BCP (fA = 0.04), and label-free PSt-b-PPEGA (fN = 0.92). The decrease in fluorescence intensity of pyrene in the micelles confirmed the occurrence of FRET, with an observed efficiency of 0.32. A Monte Carlo approach was employed to estimate the expected FRET efficiency, assuming the random fractional distribution of D-BCP and A-BCP, along with the random spatial distribution of pyrene and perylene within the micellar core. The observed FRET efficiency suggested a core radius (Rc) of 0.95R0, where R0 was the Förster critical distance. With R0 calculated to be 3.2 nm based on Förster theory, Rc was determined to be approximately 3.0 nm, aligning closely with the dried-out core radius estimated from aggregation number and polystyrene density. This stochastic FRET methodology was further applied to investigate the swelling behavior of the polymer micelles in a mixture of N,N-dimethylformamide (DMF) and water. Dynamic light scattering analysis revealed minimal change in core dimension below 60 vol % DMF content. However, FRET analysis provided a deeper insight, showing an increase in core radius with DMF content up to 20 vol %, followed by saturation up to 50 vol %, offering a more comprehensive understanding of the micelle swelling behavior.

Efficient synthesis of the cyclo-olefin copolymers at high temperature and pressure in a homogeneous mini-tubular reactor

Ethylene-norbornene copolymer (ENC) is one of the most representative cyclo-olefin copolymer (COC). Both the amorphous and semi-crystalline ENCs were efficiently synthesized by the homogeneous solution copolymerization of ethylene (E) and norbornene (NB) using rac-Et(Ind)2ZrCl2/triisobutylaluminium/(Ph3C)B(C6F5)4 ternary catalyst system in a visualized mini-tubular reactor under high temperature (90–130 °C) and given pressure (24 bar). An ultra-high activity of 7.6 × 108 g/(molZr h), as well as considerable efficiency of 14.1 kgENC/gZr was achieved in time of only 30 s at E/NB molar ratio of 3:1. Moreover, a quench-labeling method using 2-thiophenecarbonyl chloride (TPCC) was adopted to calculate the high proportion of active center [C*]/[Zr]. The novel strategy was proposed for preparation of the block semi-crystalline ENC elastomers with excellent tensile performance and high transparency via reversible chain transfer based on spatiotemporal concentration distribution in a mini-tubular reactor.

ZIF-8-mediated block copolymer micelles and its application in drug delivery

Block copolymer micelles have been widely used in drug delivery. Great efforts have been made to optimize the function of block copolymer micelles and further enhance their bioavailability. We propose a means of embedding ZIF-8 in block copolymer micelles to regulate its stability for improving the drug release kinetics. The block copolymer poly (2-(diisopropyl amino-ethyl methacrylate)-block-poly (vinylimidazole-co-poly (ethylene glycol) methyl methacrylate) (PDPA18-b-P(Vim18-co-P(EG)5MA21) (PDPV) bearing imidazole moiety was synthesized through reversible addition-cracking chain transfer (RAFT) polymerization. PDPV can self-assemble into micelles in aqueous solution and then be loaded with doxorubicin (DOX) to obtain DOX@PDPV, followed by Zn coordination to anchor ZIF-8 to the PVim moiety in DOX@PDPV to obtain the final drug delivery system DOX@PDPV@ZIF-8 hybrids. The DOX@PDPV@ZIF-8 hybrids can avoid the influence of the critical micelle concentration (CMC) on it, which was further prevent the premature leakage of DOX under physiological conditions. Furthermore, the pH-responsive properties of PDPA and ZIF-8 facilitated enabled the effective release of DOX in weakly acidic tumor environments. In vitro studies also confirmed that DOX@PDPV@ZIF-8 improved DOX accumulation in cells, leading to the inhibition of cancer cell growth. Therefore, the integrated design provided a promising strategy to regulate the stability of block copolymer micelles, improve drug release kinetics, and ultimately inhibit the growth of cancer cell.

Proton transfer anionic polymerization with C-H bond as the dormant species.

Living anionic polymerization-the most common living polymerization and the one with the longest history-generally requires stringent, water-free conditions and one metal initiator per polymer chain. Here we present the proton transfer anionic polymerization of methacrylates using acidic C-H bonds as the dormant species that are activated by base catalysts. The polymerization mechanism involves reversible chain transfer or termination of the growing enolate species. A weakly acidic compound, such as an alkyl isobutyrate, serves as the initiator or chain-transfer agent in the presence of a bulky potassium base catalyst to produce a polymer chain and, thereby, diminishes the metal compound per chain ratio. An added alcohol serves as a reversible terminator to tame the propagation. End-functionalized, star, block and graft polymers are easily accessible from compounds with C-H bonds.

Enhanced Stability-Based Hydroxymethyl Cellulose/Polyacrylamide Interpenetrating Dual Network Hydrogel Electrolyte for Flexible Yarn Zinc-Ion Batteries

As the field of wearable electronics continues to boom, the demand for flexible energy storage devices continues to grow. However, the development of soft energy supply devices with excellent stability is still a challenging task. Traditional hydrogel electrolytes are prone to mechanical deformation, which makes it difficult to maintain the functional stability of flexible yarn due to its short battery life and low wear resistance. Here, we developed a reversible energy-dissipating dual-network hydrogel electrolyte. The hydroxymethyl cellulose (CMC)/polyacrylamide (PAM) hydrogel electrolyte has a tensile deformation of 2700% and a high ionic conductivity of 6.37 × 10−2 S cm−1. The specific capacity of the assembled CMC/PAM-based yarn cell was 170 μAh cm−1 at 1 mA cm−1 and 73.14% after 100 cycles. The excellent performance is attributed to the crosslinked double network structure, in which the introduction of carboxyl groups is conducive to the improvement of hydrophilicity and ionic conductivity. The hydrogen bond and reversible CMC macromolecular chain can be restored after stress relief, which greatly improves the toughness of the material. Even under different bending angles and repeated bending conditions, zinc yarn batteries still have outstanding mechanical properties and cycle stability (71.28% specific capacity after 100 cycles), showing broad application prospects in wearable smart textiles.

3D printed micro-structured hydrogel device with transmittance-changeable soft ‘armor’ camouflage for dual-encryption

Hydrogel-based physical dual-encryption typically relies on the reversible shape-deformation of polymer chains for the decryption. However, the stored information is confronted by indecipherability at the microscale because the intrinsic relaxation of polymer chains would disrupt the fidelity of encoded information. Inspired by female Doryteuthis opalescens squid’s camouflage strategy (i.e., switching a stripe on its mantle from nearly transparent to opaque white), we devised a reversible transmittance-changeable hydrogel layer to fully cover the mono-encrypted information layer for dual-encryption. The micro-structured hydrogel was manufactured via 3D printing to encode the information, which can be decoded by UV-induced fluorescent emission. Then, the white camouflage hydrogel was constructed to conceal the mono-encrypted layer, which will not affect the information encoding layer during the reversible polymer chain mobility. The information can be decoded with alkaline solution and UV irradiation in a rapid speed, i.e., in 4 min, with good reusability. Moreover, the information was accurately unveiled even at microscale resolution, holding great promise for high-level encryption at the device level.

Macrocycle-Based Charge Transfer Cocrystals with Dynamically Reversible Chiral Self-Sorting Display Chain Length-Selective Vapochromism to Alkyl Ketones.

Chirality-driven self-sorting plays an essential role in controlling the biofunction of biosystems, such as the chiral double-helix structure of DNA from self-recognition by hydrogen bonding. However, achieving precise control over the chiral self-sorted structures and their functional properties for the bioinspired supramolecular systems still remains a challenge, not to mention realizing dynamically reversible regulation. Herein, we report an unprecedented saucer[4]arene-based charge transfer (CT) cocrystal system with dynamically reversible chiral self-sorting synergistically induced by chiral triangular macrocycle and organic vapors. It displays efficient chain length-selective vapochromism toward alkyl ketones due to precise modulation of optical properties by vapor-induced diverse structural transformations. Experimental and theoretical studies reveal that the unique vapochromic behavior is mainly attributed to the formation of homo- or heterochiral self-sorted assemblies with different alkyl ketone guests, which differ dramatically in solid-state superstructures and CT interactions, thus influencing their optical properties. This work highlights the essential role of chiral self-sorting in controlling the functional properties of synthetic supramolecular systems, and the rarely seen controllable chiral self-sorting at the solid-vapor interface deepens the understanding of efficient vapochromic sensors.

A super strong polyurethane elastomer with efficient self-healing performance enabled by partially mixing reversible hard domains

The reversible chain extender Diels-Alder-diol (DA-diol) containing thermally dissociable Diels-Alder adducts (DA adducts) was synthesized and combined with 1,4-butanediol (BDO) as complexed chain extenders used for preparing a transparent polyurethane elastomer (DAPU) with high mechanical strength and efficient self-healing ability by partially mixing reversible hard domains. The optimal DAPU occupies a desired high tensile strength of 65 MPa, and its elongation at break and toughness are of 1050 % and 216 MJ·m−3, respectively. Meanwhile, the DAPU-0.2 elastomer heals at 110 °C for 2 h with a healing efficiency of 95 %. The desirable mechanical strength and efficient self-healing ability are attributing to the BDO chain extended hard segments ensure the high strength at room temperature, while DA-diol chain extended hard segments endow the as-prepared DAPUs with self-healing ability at an elevated temperature. This work overall points to a strategy in designing self-healing polyurethane elastomers with markedly improved mechanical strength and efficient self-healing ability by partially mixing reversible hard domains.

Facile and efficient in-situ end-functionalization of neodymium-based polybutadiene by isocyanate via a coordinative chain transfer polymerization strategy

Tapping facile and efficient strategies for in-situ end-functionalization of polydiene elastomers has been pursued for scientists for decades. This has been especially prominent for Ziegler-Natta type catalytic systems, because they hold great potential for future large-scale industrializations. In this report, through using a newly emerged method of coordinative chain transfer polymerization (CCTP), we introduce a simple and convenient method to efficiently end-functionalize neodymium-based polybutadienes by in-situ addition of isocyanate or isothiocyanate compounds. These two types of substrates performed high reactivities with η1-allyl-Al capped polybutadienyl chain-ends, that were generated from fast and reversible chain transfer reactions, giving high functionalization efficiencies (up to 97.1 %). The high functionalization efficiencies were also applicable to isocyanate or isothiocyanate substrates bearing different functionalities, showing a broad scope capability. Moreover, such a functionalization process was not influenced by the viscosities of the reaction system, as revealed from the kinetic studies that linear relationship was obtained between Mns and various [BD]/[Nd] ratios, implying again the high reactivities of the isocyanate or isothiocyanate compounds. Due to the incorporation of amide or thioamide functional group into the chain-ends, the corresponding polybutadienes showed much improved surface properties and performed higher mechanical properties than unfunctionalized counterparts for raw rubber matrix. Regarding the vulcanizate, chain-end functional groups could also result in much improved filler dispersion and stronger interaction between rubber and filler particles, which eventually gave rise to better mechanical properties, inducing higher tensile strength, more toughness, and greater tear strength.

A single-step extraction and immobilization of soybean lipolytic enzymes by using a purpose-designed copolymer of styrene and maleic acid as a membrane lysis agent

Approaches aiming to recover proteins without denaturation represent attractive strategies. To accomplish this, a membrane lysis agent based on poly(styrene-alt-maleic acid) or PSMA was synthesized by photopolymerization using Irgacure® 2959 and carbon tetrabromide (CBr4) as a radical initiator and a reversible chain transfer agent, respectively. Structural elucidation of our in-house synthesized PSMA, so-called photo-PSMA, was performed by using NMR spectroscopy. The use of this photo-PSMA in soybean enzyme extraction was also demonstrated for the first time in this study. Without a severe cell rupture, energy input or any organic solvent, recovery of lipolytic enzymes directly into nanometric-sized particles was accomplished in one-step process. Due to the improved structural regularity along the photo-PSMA backbone, the most effective protective reservoir for enzyme immobilization was generated through the PSMA aggregation. Formation of such reservoir enabled soybean enzymes to be shielded from the surroundings and resolved in their full functioning state. This was convinced by the increased specific lipolytic activity to 1,950 mU/mg, significantly higher than those of sodium dodecyl sulfate (SDS) and the two commercially-available PSMA sources (1000P and 2000P). Our photo-PSMA had thus demonstrated its great potential for cell lyse application, especially for soybean hydrolase extraction.

Synthesis and characterization of styrene‐maleic acid block copolymers with acrylic and methacrylic acids for potential use in membrane protein extraction

AbstractStyrene‐maleic acid (SMA) block copolymers with acrylic acid (AA) and methacrylic acid (MAA) were synthesized via a 3‐step process comprising: (1) photopolymerization of styrene and maleic anhydride in solution to yield an alternating styrene‐maleic anhydride (SMAnh) copolymer, (2) copolymerization of SMAnh with AA and MAA to yield SMAnh‐b‐AA and SMAnh‐b‐MAA block copolymers, and (3) base‐catalyzed hydrolysis of the anhydride groups to yield water‐soluble SMA‐b‐AA and SMA‐b‐MAA block copolymers. Copolymer compositions and average molecular weights were determined by the synthesis methodology used in which reversible chain transfer was a key component. Copolymer characterization was carried out by a combination of techniques, namely: ATR‐FTIR, 1H‐NMR, dilute‐solution viscometry, GPC, DSC, and TGA. These novel SMA block copolymers have been designed with a view to their use in membrane protein (MP) extraction from plant extracts and other naturally occurring substances of potential therapeutic value. The main function of the AA or MAA blocks is to widen the operational pH range of SMA in terms of (a) maintaining its water solubility at low pH and (b) stabilizing its MP assemblies in solution.

Impact of Interfacial Halogen Bonding with a Surfactant on Miniemulsion Reversible Chain Transfer-Catalyzed Polymerization

Impact of Interfacial Halogen Bonding with a Surfactant on Miniemulsion Reversible Chain Transfer-Catalyzed Polymerization

Imidazole-mediated stability of block copolymer micelles and its application in drug delivery

Block copolymer micelles have emerged as a safer alternative for delivering drugs in biomedical applications. Recent studies have shown that the stability of these micelles can significantly impact the efficiency of drug delivery. Here, we propose a method to regulate the stability of block copolymer micelles by introducing a third monomer. Specifically, we synthesized the block copolymer PDPA18-b-P(Vim18-co-P(EG)5MA21) through reversible addition-cracking chain transfer (RAFT) polymerization based on PDPA19-b-P(P(EG)5MA)18. The diblock three-component copolymer is a unique copolymer, in which the hydrophilic block being doped the third monomer with pH-sensitive property, resulting in distinctive physiological properties. Both PDPA18-b-P(Vim18-co-P(EG)5MA21) and PDPA19-b-P(P(EG)5MA)18 can self-assemble into micelles with a core-shell structure. In the case of PDPA19-b-P(P(EG)5MA)18 micelles, the solvophobic PDPA19 block forms the core, while the solvophilic P(P(EG)5MA)18 block forms the shell. To regulate the stability of the block copolymer micelles, an imidazole intermediate layer with pH-responsiveness is introduced between PDPA core and P(P(EG)5MA) shell. The introduction of the imidazole monomer affect the stability of block copolymer micelles and the release kinetics of drugs. We validated that these PDPA18-b-P(Vim18-co-P(EG)5MA21) micelles exhibit higher stability under neutral conditions and show enhanced drug release in mildly acidic conditions compared to PDPA19-b-P(P(EG)5MA)18 micelles. Overall, this report demonstrates that copolymerization of imidazole monomer is a powerful approach to mediated the stability of block copolymer micelles for drug delivery applications.

MULTIMODALITY IMAGING OF COVID-19 PNEUMONIA : A SYSTEMATIC REVIEW

Background: Reversible transcription polymerase chain reaction (RT-PCR) nasopharyngeal or oropharyngeal swab tests that yield a positive result can establish the diagnosis of COVID-19. Due to the high prevalence of false-negative findings, especially in the early stages of the disease, and the patchy availability of testing, a methodical approach to diagnosis that incorporates radiologic imaging is required. Aims : This systematic review is to review the multimodality imaging of patients with COVID-19 pneumonia. Methods: By comparing itself to the standards set by the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) 2020, this study was able to show that it met all of the requirements. So, the experts were able to make sure that the study was as up-to-date as it was possible to be. For this search approach, publications that came out between 2014 and 2024 were taken into account. Several different online reference sources, like Pubmed and SAGEPUB, were used to do this. It was decided not to take into account review pieces, works that had already been published, or works that were only half done. Result: In the PubMed database, the results of our search brought up 22.043 articles, whereas the results of our search on SAGEPUB brought up 19.007 articles. The results of the search conducted for the last year of 2014 yielded a total 173 articles for PubMed and 98 articles for SAGEPUB. In the end, we compiled a total of 6 papers, 5 of which came from PubMed and 1 of which came from SAGEPUB. We included five research that met the criteria. Conclusion: In summary, owing to the SARS-CoV-2 pandemic, it is critical to understand the typical and atypical imaging features of COVID-19 pneumonia as well as how they change over time on CXR and HRCT. When evaluating hospitalized and critically sick patients in a serial fashion, as well as in places with high levels of contagion, computed tomography (CXR) may be the initial imaging modality employed

Synthesis and modification of copolymers of stearyl methacrylate and maleic anhydride and study of their effect on low-temperature characteristics of diesel fuel

Polymer-analogous transformations have been used to modify copolymers of stearyl methacrylate with maleic anhydride synthesized under radical polymerization conditions using reversible chain transfer agents of various structures. It has been established that copolymer of stearyl methacrylate with maleic anhydride modified by 25% with octanol-1 has a high depressant effect for a pour point of minus 19°С and at the same time significantly reduces both the cloud point values and the maximum filterability temperature of diesel fuel. In this regard, the obtained modified copolymers may be of interest in terms of their practical use as fuel additives.

Pyrazole carbodithiolate-driven iterative RAFT single-additions.

In this Communication, we comprehensively investigated substituent effects relevant to iterative reversible activation fragmentation chain transfer (RAFT) single unit monomer insertion (SUMI) reactions. Through the use of the pyrazole carbodithiolate (PCDT) "Z-group" as the chain transfer component in RAFT SUMI, we show the importance of "Z-group" effects and its interplay with "R-group" (the carbon-centred radical precursor) effects. We also expanded the scope of RAFT SUMI to new monomer types and sequences thereof. As such, the C-S bond dissocation/reformation steps were found to be crucial factors in SUMI, and it was found that general substituent effects must be wholistically examined for every step of this reaction. This stands in contrast with conventional knowledge of RAFT polymerisation, where the main consideration is often centred around the propagation stage, i.e., the key C-C bond formation step. Indeed, contrary to SUMI, the latter characteristic was observed in the analogous alternating copolymerisation.

SYNTHESIS OF COPOLYMERS OF STEARYLMETHACRYLATE AND STEARYLACRYLATE WITH N-SUBSTITUTED ACRYLAMIDES IN THE PRESENCE OF REVERSIBLE CHAIN TRANSFER AGENTS AND STUDY OF THEIR EFFECT ON THE LOW-TEMPERATURE PROPERTIES OF DIESEL FUEL

The features of copolymerization of stearylacrylate (SA) and stearylmethacrylate with N-isopropylacrylamide and N,N-dimethylacrylamide in the presence of dibenzyltrithiocarbonate and 2-cyanoisopropyldodecyltrithiocarbonate as agents of reversible chain transfer have been studied. The choice of agents of reversible chain transfer (RAFT-agents) is due to the fact that sulfur-containing compounds with cyanoisopropyl radicals are most effective in the polymerization of methacrylic monomers, while benzyltrithiocarbonates are more active in the polymerization of acrylic monomers, as well as styrene and acrylonitrile. It has been established that polymerization of stearyl methacrylate (SMA) in the presence of RAFT-agents proceeds without a gel effect up to a high conversion. At the same time, although polystеarylmethacrylate samples are characterized by relatively high values of polydispersity coefficients (Mn/Mw) for controlled radical polymerization processes, they are nevertheless somewhat lower than for polymers of similar conversion synthesized in the absence of chain transfer agents. It has been shown that the process of copolymerization of stearyl acrylate and stearylmethacrylate with N-isopropylacrylamide and N,N-dimethylacrylamide in the presence of dibenzyltrithiocarbonate and 2-cyanoisopropyldodecyltrithiocarbonate proceeds without gelation to high conversions. The synthesized copolymers are characterized by a relatively narrow molecular weight distribution: the polydispersity coefficients of polymer samples vary from 1.18 to 1.57 in the case of using N-isopropylacrylamide and from 1.21 to 1.47 when using N,N-dimethylacrylamide as a comonomer to higher alkyl acrylates, which is typical for processes of radical polymerization proceeding in a controlled manner. At the same time, the synthesized copolymers exhibit a significant depressant effect when they are introduced into diesel fuel at a concentration of 1600 ppm. It has been established that copolymers of stearylmethacrylate and stearylacrylate with polar nitrogen-containing monomers have a more effective effect on the low-temperature properties of diesel fuel than homopolymers of stearylmethacrylate and stearylacrylate. At the same time, additives based on copolymers of stearylmethacrylate with N-isopropylacrylamide with a composition of 70/30 mol.% and stearylacrylate with N-isopropylacrylamide with a composition of 20/80 mol.% had the most significant effect on the low-temperature characteristics of the fuel.

Nitrogen-Doped Graphene Quantum Dots as Electrochemiluminescence-Emitting Species for Sensitive Detection of KRAS G12C Mutation via PET-RAFT.

The levels of KRAS G12C point mutation is recognized to be closely related to the earlier diagnosis of non-small cell lung cancer (NSCLC). Here, based on nitrogen-doped graphene quantum dots (NGQDs) and photo-induced electron/energy transfer reversible addition-fragment chain transfer (PET-RAFT) signal amplification strategy, we fabricated a novel electrochemiluminescence (ECL) biosensor for the detection of KRAS G12C mutation for the first time. NGQDs as ECL-emitting species with cathodic ECL were prepared by a simple calcination method. Firstly, KRAS G12C mutation DNA, i. e., target DNA (tDNA), was captured by specific identification with hairpin DNA (hDNA). Then, PET-RAFT was initiated by blue light, and large numbers of monomers were successfully polymerized to form controllable polymer chains. Lastly, massive NGQDs was introduced via amidation reaction with N-(3-aminopropyl)methacrylamide hydrochloride (APMA), which significantly amplified the ECL signal intensity. Under optimal conditions, this biosensor achieved a good linear relationship between ECL intensity and logarithm of the levels of KRAS G12C mutation in the range from 10 fM to 10 nM. Moreover, this strategy exhibited high selectivity and excellent applicability for KRAS G12C mutation detection in the serum samples. Therefore, this biosensor has great potential in clinical diagnosis and practical application.