Atom Transfer Radical Polymerization Reaction Research Articles

Development of Methylene Bis-Benzotriazolyl Tetramethylbutylphenol-grafted lignin sub-microspheres loaded with TiO2 for sunscreen applications

Lignin serves as a promising Ultraviolet (UV) absorber within sunscreen industry. However, the commercial development of lignin-containing sunscreens faces challenges due to their low sun protection factor (SPF) and dark color in cosmetics industry. In this study, dual modifications on the chemical and physical structures of lignin were conducted to address these challenges. Initially, methylene bis-benzotriazolyl tetramethylbutylphenol (MBBT) was grafted onto alkali lignin (AL) through an atom transfer radical polymerization reaction, resulting in a polymer of AL-graft-MBBT3 (AL-g-MBBT3). The sunscreen prepared with 10 % AL-g-MBBT3 displays outstanding sun protection performance with a SPF of 42.93 and a light color with a color difference value (ΔE) of 45.6, in contrast to 10 % AL with a SPF of 4.74 and a ΔE value of 49.5. Subsequently, AL-g-MBBT3 was transformed into normal submicron spheres (AL-g-MBBT3 N) and TiO2-loading submicron spheres (AL-g-MBBT3/TiO2). The sun protection performances of 10 % AL-g-MBBT3 N@C and AL-g-MBBT3/TiO2@C sunscreens obviously surpass that of AL-g-MBBT3@C sunscreen, achieving SPFs of 60.38 and 66.20, respectively. Additionally, there is a considerable improvement in the color of these sunscreens, with ΔE values of 41.8 and 36.3, respectively. These results provide valuable insights into exploring lignin's high-value applications in sunscreen.

Durable and dense zwitterionic polymer brushes initiated from surface-segregated cyclic initiator via atom transfer radical polymerization

Immobilization of initiators on a polymer surface for surface-initiated polymerization has primarily been achieved via covalent bonds. However, this approach is subject to limitations, such as the requirement for additional processing steps and different customized methods tailored to the specific characteristics of each polymer. In this study, initiator immobilization was achieved by surface segregation, a phenomenon observed in polymer blends wherein one component spontaneously enriches the surface, thereby enabling the modification of surface properties. Specifically, we designed cyclic oligomers containing an atom transfer radical polymerization (ATRP) initiator. The enhanced performance of surface segregation mediated by the cyclic topology was evaluated, along with the surface-initiated polymerization initiated by the surface-segregated oligomer. The kinetics of the ATRP reaction for the cyclic initiators were investigated, and the zwitterion polymer brush density was also calculated. The robustness of the brushes was evaluated through leaching tests, which revealed no notable alterations before and after the assessments. The antifouling effect of the brushes was confirmed through protein adsorption, platelet adhesion, bacterial attachment, and whole-blood circulation experiments. These antifouling examinations demonstrated reduced substance attachment of zwitterionic polymer brushes. Lastly, experiments on optimizing the ATRP catalyst loading during the surface-initiated ATRP were conducted. The excellent performance of the cyclic initiators is expected to provide new insights and opportunities in the field of surface-initiated polymerization. Moreover, the formation of zwitterion brushes via cyclic initiators holds promise for versatile applications in the field of long-term utilization in biointerfaces, offering a wide range of potential uses.

Controlled polymerization in microfluidics: Advancement in nanogel synthesis

AbstractThis comprehensive review provides a detailed examination of controlled polymerization in the development of nanogels‐based microfluidic devices. Here, we have explored the integration of atom transfer radical polymerization (ATRP) and reversible addition‐fragmentation chain transfer (RAFT) techniques within microfluidic platforms for the synthesis of nanogels. The synergistic combination of ATRP and RAFT with microfluidics has emerged as a powerful tool for precise control over polymerization reactions, enabling the fabrication of well‐defined, multifunctional nanogels with tailored properties. The review begins with a thorough introduction to the principles of ATRP and RAFT, highlighting their respective advantages in controlled radical polymerization. Subsequently, it elucidates the principles of microfluidics and its profound impact on polymerization processes. The merging of these techniques enables precise control over reaction kinetics, monomer conversions, and molecular weight distributions, facilitating the synthesis of nanogels with unprecedented precision and reproducibility. Furthermore, this review delves into the chemical mechanisms underlying ATRP and RAFT reactions in microfluidic environments, emphasizing the role of various initiators, catalysts, and chain transfer agents. Special attention is given to the impact of microscale flow conditions on reaction kinetics and polymer structure. In addition, the review discusses emerging trends in the field, such as the incorporation of novel monomers and the exploration of environmentally benign reaction conditions.Highlights The controlled polymerization is the mechanism by which we can obtain tailormade material. The nanogel synthesis must ensure the gelation to be in confined dimensions here microfluidics plays key role.

A novel electrochemical biosensor based on dual signal amplification of CMK-3@AuNPs and ATRP for DR1 detection

Down-regulator of transcription 1 (DR1) is a crucial biomarker closely related to Hashimoto's Thyroiditis (HT). In this study, a highly selective electrochemical biosensor for ultrasensitive detection of DR1 was prepared by combining nanomaterials CMK-3 @AuNPs and atom transfer radical polymerization (ATRP) signal amplification strategy for the first time. Based on the specific recognition of antigen and antibody, the sensor has strong selectivity. CMK-3 @AuNPs can not only increase the conductivity of the electrode, but also provide more active sites for biological molecules, so as to effectively amplify the output signal. The FMMA monomers were polymerized on the electrode surface through ATRP reaction, which made the electrochemical signal increased significantly. Under optimal conditions, the fabricated electrochemical biosensor showed a wide detection range of 5 × 10-4 ng/mL ∼ 5 × 102 ng/mL with a detection limit as low as 0.159 pg/mL. In addition, the electrochemical biosensor has good stability and anti-interference ability. Therefore, the sensor has broad prospects in the detection of biomarkers.

Development of a peptide microarray-based metal-enhanced fluorescence assay for ultrasensitive detection of multiple matrix metalloproteinase activities by using a gold nanorod-polymer substrate

Matrix metalloproteinases (MMPs) are attractive biomarkers for cancer diagnosis and treatment, while it is still a challenge to precise analysis of MMP activities owing to their very low abundance in the biological samples, especially at the early stages of tumors. Herein, a peptide microarray-based metal-enhanced fluorescence assay (PMMEFA) is proposed to simultaneously detect MMP-1, -2, -3, -7, -9, and -13 activities. The assay involves immobilization of Förster resonance energy transfer dye pair decorated peptides (FRET-peptides) on a poly(glycidyl methacrylate-co-2-hydroxyethyl methacrylate) coated gold nanorod modified glass slide (GNR@P(GMA-HEMA)). To fabricate the GNR@P(GMA-HEMA) slide, GNRs are self-assembled onto an aminated glass slide, and a polymer brush (P(GMA-HEMA)) is grown through a surface-initiated atom transfer radical polymerization reaction (SI-ATRP). Upon the addition of MMPs, the FRET pairs are broken due to the specific cleavage of FRET-peptides by enzymes, resulting in the recovery of fluorescence signals and further enhancement by the MEF of GNRs. The fluorescence recovery degree provides a direct indicator for MMP activity. The PMMEFA exhibits excellent sensitivity, which enables to detect MMP-1, -2, -3, -7, -9, and -13 activities, with low limits of detection (LODs) of 1.7 fg mL−1, 0.3 fg mL−1, 2.0 fg mL−1, 1.8 fg mL−1, 2.2 fg mL−1 and 14.0 fg mL−1, respectively. To substantiate the practicability of PMMEFA, MMP activities were measured in a range of matrices, encompassing cell culture medium, serum, and tumor tissue homogenate, and MMP activities can be detected only in 0.15 μL serum and 0.025 mg tumor tissue.

FADH2-mediated radical polymerization amplification for microRNA-21 detection

For early diagnosis of disease, ultrasensitive mircoRNA-21 detection has considerable potential. In this paper, an ultra-sensitive fluorescence detection method for microRNA was developed by atom transfer radical polymerization (ATRP). This ATRP reaction was first initiated by using flavin mononucleotide (FADH2). The DNA probe 1 modified with amino group was fixed on the magnetic nanoparticle Fe3O4, and microRNA-21 was added to form the probe 1-microRNA-21. Another carboxy-modified DNA 2 forms a sandwich structure with the bound microRNA-21. Two terminally modified DNA types are used as microRNA probes, using complementary base pairing to form a stable super-sandwich structure between the DNA probe and the microRNA. Under optimal conditions, microRNA was detected in PBS buffer with a detection limit of 0.19 fM. And even in 10% of human serum, microRNA-21 can be detected with a detection limit of 47.8 fM. Results show that this method has high selectivity, efficiency and stability, which broad application prospect in microRNA ultra-sensitive detection.

A versatile drug-controlled release polymer brush hybrid non-glutaraldehyde bioprosthetic heart valves with enhanced anti-inflammatory, anticoagulant and anti-calcification properties, and superior mechanical performance

Transcatheter heart valve replacement (THVR) is a novel treatment modality for severe heart valves diseases and has become the main method for the treatment of heart valve diseases in recent years. However, the lifespan of the commercial glutaraldehyde cross-linked bioprosthetic heart valves (BHVs) used in THVR can only serve for 10–15 years, and the essential reason for the failure of the valve leaflet material is due to these problems such as calcification, coagulation, and inflammation caused by glutaraldehyde cross-linking. Herein, a kind of novel non-glutaraldehyde cross-linking agent bromo-bicyclic-oxazolidine (OX-Br) has been designed and synthesized with both crosslinking ability and in-situ atom transfer radical polymerization (ATRP) function. Then OX-Br treated porcine pericardium (OX-Br-PP) are stepwise modified with co-polymer brushes of reactive oxygen species (ROS) response anti-inflammatory drug conjugated block and anti-adhesion polyzwitterion polymer block through the in-situ ATRP reaction to obtain the functional BHV material MPQ@OX-PP. Along with the great mechanical properties and anti-enzymatic degradation ability similar to glutaraldehyde-crosslinked porcine pericardium (Glut-PP), good biocompatibility, improved anti-inflammatory effect, robust anti-coagulant ability and superior anti-calcification property have been verified for MPQ@OX-PP by a series of in vitro and in vivo investigations, indicating the excellent application potential as a multifunctional heart valve cross-linking agent for OX-Br. Meanwhile, the strategy of synergistic effect with in situ generations of reactive oxygen species-responsive anti-inflammatory drug blocks and anti-adhesion polymer brushes can effectively meet the requirement of multifaceted performance of bioprosthetic heart valves and provide a valuable reference for other blood contacting materials and functional implantable materials with great comprehensive performance.

Syndiotactic Poly(4-methyl-1-pentene)-Based Stereoregular Diblock Copolymers: Synthesis and Self-Assembly Studies.

Syndiotactic poly(4-methyl-1-pentene) (sP4M1P)-based stereoregular diblock copolymers, namely sP4M1P-b-polystyrene and sP4M1P-b-polymethylmethacrylate, were prepared from an α-bromoester-capped sP4M1P macroinitiator, which was chain extended with styrene and methyl methacrylate, respectively, via the atom transfer radical polymerization reaction. The α-bromoester-capped sP4M1P was generated by the esterification of hydroxyl-capped sP4M1P with α-bromoisobutyryl bromide. The hydroxyl-capped sP4M1P was synthesized by inducing a selective chain transfer reaction to aluminum during the syndiospecific polymerization of 4-methyl-1-pentene in the presence of a syndiospecific metallocene catalyst. As stereoregular diblock copolymers are difficult to prepare using existing methods, the current study offers an effective process for the preparation of sP4M1P-based stereoregular diblock copolymers. These copolymers were found to have well-defined architectures and they can undergo molecular self-assembly into ordered nanostructures, as evidenced by small-angle X-ray scattering analyses.

A thermoresponsive cationic block copolymer brush-grafted silica bead interface for temperature-modulated separation of adipose-derived stem cells

Adipose-derived mesenchymal stem cells (ADSCs) have beneficial effects in cell transplantation therapy; these cells are collected from adipose tissue using low-invasive methods. However, to prepare ADSCs for cell therapy, a cell separation method that neither involves modification of the cell surface nor causes loss of cell activity is needed. Here, we aimed to develop ADSC separation columns using thermoresponsive cationic block copolymer brush-grafted beads as packing materials. The block copolymer brush was formed by a bottom cationic segment, poly(N,N-dimethylaminopropylacrylamide) (PDMAPAAm), and an upper thermoresponsive segment, poly(N-isopropylacrylamide) (PNIPAAm), and was grafted in two atom transfer radical polymerization reactions. The copolymer brush-grafted silica beads were packed into a column. An ADSC suspension was introduced into the columns at 37 °C and adsorbed on the copolymer brush-modified beads through electrostatic and hydrophobic interactions with the PDMAPAAm and PNIPAAm segments, respectively. The adsorbed ADSCs eluted from the column by lowering the temperature to 4 °C. In contrast, most Jurkat and vascular endothelial cells eluted at 37 °C, because of the relatively weaker electrostatic interactions with the block copolymer brush compared to ADSCs. Using the prepared column, a mixture of ADSCs and Jurkat cells was separated by changing the column temperature. The recovered ADSCs exhibited cell activity. The developed cell separation column may be useful for isolating ADSCs without cell surface modification, while maintaining cell activity.

Advances in atom transfer radical polymerization of modified grain

Atom transfer radical polymerization (ATRP) is a kind of controllable reactive radical polymerization method with potential application value. The modification of graphene oxide (GO) by ATRP reaction can effectively control various graft polymer molecules Chain length and graft density, giving GO different functionality, such as good solvent dispersibility, environmental sensitive stimulus responsiveness, biocompatibility, and the like. In this paper, ATRP reaction and GO surface non-covalent bonding ATRP polymer molecular chain were directly initiated from GO surface immobilization initiator. The ATRP reaction modified GO was reviewed, and the process conditions and research methods of ATRP modification reaction were summarized, as well as pointed out the functional characteristics and application prospect of GO functionalized composites.

Atom Transfer Radical Polymerization: A Mechanistic Perspective.

Since its inception, atom transfer radical polymerization (ATRP) has seen continuous evolution in terms of the design of the catalyst and reaction conditions; today, it is one of the most useful techniques to prepare well-defined polymers as well as one of the most notable examples of catalysis in polymer chemistry. This Perspective highlights fundamental advances in the design of ATRP reactions and catalysts, focusing on the crucial role that mechanistic studies play in understanding, rationalizing, and predicting polymerization outcomes. A critical summary of traditional ATRP systems is provided first; we then focus on the most recent developments to improve catalyst selectivity, control polymerizations via external stimuli, and employ new photochemical or dual catalytic systems with an outlook to future research directions and open challenges.

Modified cellulose nanocrystals based on SI‐ATRP for enhancing interfacial compatibility and mechanical performance of biodegradable PLA/PBAT blend

AbstractTo make up for the brittleness of poly(lactic acid) (PLA), people usually introduce flexible poly(butylene adipate‐co‐terephthalate) (PBAT) which greatly reduces the strength and limits toughening effect due to unfavorable immiscibility of the blends. Herein, functionalized biodegradable cellulose nanocrystals (CNCs) were used as enhancement to simultaneously improve strength and toughness of PLA/PBAT blend. To improve the interaction between PLA and PBAT, poly(glycidyl methacrylate) (PGMA) was grafted on the surface of CNC via a surface‐initiated atom transfer radical polymerization reaction. After the addition of CNC‐PGMA30, the phase size of PLA/PBAT (70/30 wt%) reduces dramatically, showing improved interfacial compatibility between PLA and PBAT. Meanwhile, prepared PLA/PBAT/CNC1.0‐PGMA30 composite has tensile strength of 49.6 MPa and elongation at break of 268.5%, demonstrating considerably increased strength and toughness in comparison to the pure PLA/PBAT blend.

Effect of atom transfer radical polymerization reaction time on PCB binding capacities of Styrene-CMA/QMA Core-Shell iron oxide nanoparticles

Water pollution continues to be one of the greatest challenges humankind faces worldwide. Increasing population growth, fast industrialization and modernization risk the worsening of water accessibility and quality in the coming years. Nanoadsorbents have steadily gained attention as remediation technologies that can meet stringent water quality demands. In this work, core–shell magnetic nanoparticles (MNPs) comprised of an iron oxide magnetic core and a styrene based polymer shell were synthesized via surface initiated atom transfer radical polymerization (SI-ATRP) and characterized for their binding of polychlorinated biphenyls (PCBs), as model organic contaminants. Acrylated plant derived polyphenols, curcumin multiacrylate (CMA) and quercetin multiacrylate (QMA), and divinylbenzene (DVB) were incorporated into the polymeric shell to create high affinity binding sites for PCBs. The affinity of these novel materials for PCB 126 was evaluated and fitted to the nonlinear Langmuir model to determine binding affinities (KD). The KD values obtained for all the MNP systems showed higher binding affinities for PCB 126 that carbonaceous materials, like activated carbon and graphene oxide, the most widely used adsorption materials for water remediation today. The effect of increasing ATRP reaction time on the binding affinity of MNPs demonstrated the ability to tune polymer shell thickness by modifying the reaction extent and initial crosslinker concentrations in order to maximize pollutant binding. The enhancement in binding affinity and capacity for PCB 126 was demonstrated by the use of hydrophobic, aromatic rich molecules like styrene, CMA, QMA and DVB, within the polymeric shell provides more sites for π-π interactions to occur between the MNP surface and the PCB molecules. Overall, the high affinities for PCBs, as model organic pollutants, and magnetic capabilities of the core–shell MNPs synthesized provide a strong rationale for their application as nanoadsorbents in the environmental remediation of specific harmful contaminants.

A dual-signaling electrochemical ratiometric strategy combining “signal-off” and “signal-on” approaches for detection of MicroRNAs

A dual-signaling electrochemical ratio metric strategy was developed for detection microRNA-18a based on the duplex-specific nuclease-assisted target recycling and electrochemical atom transfer radical polymerization signal amplification. In the presence of target microRNA, RNA/DNA duplexes are formed, which become the substrate of the duplex-specific nuclease-assisted target recycling. Hence only the DNA strand is cleaved by duplex-specific nuclease enzyme, resulting in the throw away of methylene blue (MB) from the electrode (signal off) accompanied by releasing of target microRNA, which can be recycled in the next hybridization. The remaining piece of capture DNAs on the electrode surface hybridize with the Azide labeled-signal DNAs. “Click reactions” were carried out between 3-Butynyl-2-bromoisobutyrate and Azide to initiate the electrochemical atom transfer radical polymerization reaction. This process could bring a great number of ferrocenylmethyl methacrylate (FMMA) on the surface of electrode (signal on). The IFMMA/IMB value was proportionate to the microRNA-18a concentration and measured by square wave voltammetry.The promising potential of the proposed biosensor in clinical analyses was exhibited by its remarkable features such as strong performance, high specificity, agreeable storage stability, and notable selectivity in real sample evaluation with no pretreatment or amplification. Finally, our biosensing method offers such an application to be used for the early clinical diagnosis of Pancreatic Cancer.

Assemblies of Polyacrylonitrile-Derived Photoactive Polymers as Blue and Green Light Photo-Cocatalysts for Cu-Catalyzed ATRP in Water and Organic Solvents.

Photoluminescent nanosized quasi-spherical polymeric assemblies prepared by the hydrothermal reaction of polyacrylonitrile (PAN), ht-PLPPAN, were demonstrated to have the ability to photo-induce atom transfer radical polymerization (ATRP) catalyzed by low, parts per million concentrations of CuII complex with tris(2-pyridylmethyl)amine (TPMA). Such photo induced ATRP reactions of acrylate and methacrylate monomers were performed in water or organic solvents, using ht-PLPPAN as the photo-cocatalyst under blue or green light irradiation. Mechanistic studies indicate that ht-PLPPAN helps to sustain the polymerization by facilitating the activation of alkyl bromide species by two modes: 1) green or blue light-driven photoreduction of the CuII catalyst to the activating CuI form, and 2) direct activation of dormant alkyl bromide species which occurs only under blue light. The photoreduction of the CuII complex by ht-PLPPAN was confirmed by linear sweep voltammetry performed under illumination. Analysis of the polymerization kinetics in aqueous media indicated even though CuI complexes comprised only 1–1.4% of all Cu species at equilibrium, they exhibited high activation rate constant and activated the alkyl bromide initiators five to six orders of magnitude faster than ht-PLPPAN.

Regenerative magnetic nanoparticle-supported ATRP ligand for bottlebrush copolymer preparation

A facile method is proposed to prepare functionalized Fe3O4@Me6TREN nanoparticles (NPs) for atom transfer radical polymerization (ATRP). The Me6TREN moieties on NPs surface can bind copper, thus making them effective nano ligands for ATRP reactions to synthesize bottlebrush copolymers. After polymerization, purification of the polymer achieved only by a magnet, is much simpler than traditional ATRP process. No column chromatography is required. Furthermore, Fe3O4@Me6TREN NPs can thus be regenerated via separating copper from NPs surface by ligand exchange with EDTA-Na2. Such a versatile nano ligand is of great worth to promote the industrial application of ATRP at a large scale and low cost.

Visible-light-induced controlled ATRP by modified N-rich holey carbon nitride nanosheets in natural solvent

The design and preparation of green and recyclable catalysts for improving the selectively and efficiency of atom transfer radical polymerization reactions is a critical challenge in polymerization scope. Herein, two-dimensional N-rich carbon nitride nanosheets (g-C3N4 NSs) with high surface area and chemical stability were synthesized. Then, the surface of g-C3N4 NSs was modified with N-(2-acetamido)-2-aminoethanesulfonic acid as a chelating agent to obtain ACES@ g-C3N4 NSs. Finally, copper (II) was introduced to the ACES@ g-C3N4 NSs. The as-synthesized Cu-ACES@g-C3N4 NSs were characterized by various analyses. The ionic interaction, arising from sulfonate and iminium ions, increases the dispersity and stability of the catalyst in a deep eutectic solvent (DES). So, the photocatalyst was successfully utilized for “green” atom transfer radical polymerization of styrene and methyl methacrylate by the irradiation of the reaction mixture under sunlight and visible light in deep eutectic solvent as a green polymerization reaction media. The polymers with good conversions and relatively low polydispersity were obtained which characterization analyses confirmed their structure and properties. Notably, the advantages of the presented photocatalyst include easy separation and reusability without loss of activity due to its heterogeneous nature, as well as using DES as a green solvent which promotes the reaction efficiency.

Rational Design of Highly Activating Ligands for Cu-Based Atom Transfer Radical Polymerization.

Atom transfer radical polymerization (ATRP) is the most commonly utilized technique in controlled radical polymerization. However, the identification of more active catalysts could further increase its scope, both for polymerization and small-molecule synthesis more generally. To this end, a series of novel ligands were designed on the basis of two strategies: replacing nitrogen-based ligands with their phosphorus equivalents and rigidifying the ligand cap of nitrogen-based ligands so as to enforce short Cu-cap distances. Each ligand was assessed using accurate computational chemistry, which was used to compute the thermodynamics and, in selected cases, kinetics of an ATRP reaction with a model methyl methacrylate propagating radical. In principle, the use of phosphorus ligand caps was found to be a powerful strategy for increasing catalyst activity. Unfortunately, in practice, speciation issues sacrificed much of their advantage. In contrast, cap rigidification increases the activity of nitrogen-based ligands, well beyond existing ATRP ligands such as TPMANMe2. The effectiveness of these ligands was further demonstrated for hard-to-activate initiating systems based on ethylene, vinyl chloride, and vinyl acetate polymerization. Several of these improved ligands are synthetically accessible, with rigid piperidine or quinuclidine analogues of TPMANMe2 possessing improved thermodynamic and kinetic activity by 2 to 3 orders of magnitude.

Surface-initiated ATRP of glycidyl methacrylate in the presence of divinylbenzene on porous polystyrene-based resins for boron adsorption

A boron sorbent having poly(glycidyl methacrylate) chains on the surface of porous polystyrene-based beads was prepared through atom transfer radical polymerization (ATRP), followed by the reaction with a boron selective N-methyl-d-glucamine (NMDG). The grafting yield was controlled by the ATRP reaction time and the amount of crosslinking agent, divinylbenzene (DVB). Here, we have found that the high grafting yield does not guarantee high boron adsorption capacity. As the grafting yield increases to accommodate more boron chelating sites, the boron adsorption capacity increases to 1.5–2 times compared to the resin without grafting chains, but decreases dramatically at over 100% grafting yield. This loss of linear relation between boron adsorption capacity and grafting yield is probably due to the decreased porosity and pore size. The morphological contribution of the grafted chains on the boron capacity would provide new directions to design sorbent architecture for better adsorption capability.

Ultrasensitive fluorescent detection of HTLV-II DNA based on magnetic nanoparticles and atom transfer radical polymerization signal amplification

Human T-lymphotropic virus type II (HTLV-II) is a crucial retrovirus that is closely associated with a variety of human diseases. Herein, an ultrasensitive fluorescent HTLV-II DNA detection strategy was developed for the first time based on magnetic nanoparticles (MNPs) and atom transfer radical polymerization (ATRP) amplification. In this approach, hairpin DNA probes (pDNA) labelled with 5′ thiol and 3′ azide group terminally were immobilized on amino group modified MNPs surface through sulfo-N-succinimidyl-4-maleimidobutyrate sodium salt (sulfo-GMBS) cross-linkers. In the presence of target DNAs (tDNA), pDNA hybridized with tDNA to form double-stranded DNA, and therefore its azide group was away from the MNPs surface. Subsequently, to initiate ATRP reaction, initiators were introduced into the pDNA by a Cu (I)-catalyzed alkyne-azide cycloaddition (CuAAC). Then, large numbers of 9-anthracenylmethyl methacrylate polymer (pAMMA) were successfully labelled on the MNPs surface, resulting in significant amplification of the fluorescence signal. Under optimized conditions, the fluorescence signal was proportional to the logarithm of the concentration of tDNA over the range from 1 fM to 1 nM, with a detection limit of 0.22 fM. Moreover, this strategy was capable of discriminating mismatched bases and detecting HTLV-II DNA in human serum samples. By virtue of the high sensitivity, selectivity, simplicity and economy, this ultrasensitive biosensor demonstrates great potential for biomedical research and early clinical diagnosis.