Kanamycin In Milk Research Articles

Catalytic hairpin assembly-driven DNA walker to develop a label-free electrochemical aptasensor for antibiotic detection.

Anelectrochemical aptasensor was developed by utilizing a DNA walker driven by catalytic hairpin assembly (CHA) with kanamycin as the model analyte. Kanamycin bound to the aptamer, causesthe release of DNA walker, triggers the CHA reaction, leadsto the cyclic movement of the walker's long arm, and resultsin cascade amplification of thesignal. The guanine-rich sequences of the double-stranded products produced by CHA were folded to form G-quadruplex structures, with electrochemical active molecules Hemin embedded, formsG-quadruplex/Hemin complexes in situ on the electrode surface, thereby achieving sensitive, efficient, and label-free detection of kanamycin with a limit of detection (LOD) of 0.27pM (S/N = 3). Meaningfully, the aptasensor demonstrated high sensitivity and reliability in the detection of kanamycin in milk and livestock wastewater samples, suggesting that it has great potential for application in detecting antibiotics in food products and water samples from the environment.

A enzyme-free fluorescence quenching sensor for amplified detection of kanamycin in milk based on competitive triggering strategies.

In this work, we constructed a FAM fluorescence quenching biosensor based on an aptamer competition recognition and enzyme-free amplification strategy. We design a competing unit consisting of an aptamer chain and a complementary chain, and a catalytic hairpin self-assembly (CHA) unit consisting of two hairpins in which the complementary chain can trigger the catalytic hairpin self-assembly. In the initial state, the aptamer chain is combined with the complementary chain, the catalytic hairpin self-assembly unit is inhibited, the FAM fluorescence group was far away from the BHQ1 quenching group, and the fluorescence is turn-on. In the presence of kanamycin, the aptamer chain recognizes kanamycin and doesn't form double chains, resulting in the free complementary chain triggering hairpin 1 (H1), and then H1 triggering hairpin 2 (H2), FAM fluorophore is close to the BHQ1 quenching group, and the fluorescence is off-on. When H1 and H2 form a cyclic reaction, enzyme-free amplification is achieved and there is significant output of the fluorescence signal. Therefore, the biosensor has good performance in detecting kanamycin, the detection line is 54 nM, the linear range is 54 nM-0.9 μM, and it can achieve highly selective detection of kanamycin. Kanamycin residue may cause serious harm to human health. The high sensitivity detection of kanamycin is urgent, so this project has a great application potential for food detection.

An exonuclease I-assisted quencher-free 2-aminopurine aptasensor based on a multipath paper-based device for ultrasensitive detection of kanamycin

A quencher-free multipath microfluidic paper-based analytical device (µPAD) was constructed for ultrasensitive detection of kanamycin based on exonuclease I (Exo I)-assisted signal enhancement of 2-aminopurine (2-AP). Here, Exo I, a single-stranded DNA-specific nuclease, was introduced to fully liberate 2-AP mononucleotides to greatly enhance biosensing sensitivity. 2-AP, a fluorescent adenine analogue embedded in single-stranded DNA (ssDNA), was employed as the detection signal source. The fluorescence of 2-AP is strong in the mononucleotide state, while it can have low fluorescence and even no fluorescence in ssDNA and dsDNA, respectively. The 2-AP fluorescence probe included 2-AP DNA and kanamycin aptamer. When kanamycin was present, binding occurred between kanamycin and the aptamer, leading to ssDNA, which was further digested by Exo I. In this case, free 2-AP mononucleotides were liberated, indicating strong fluorescence. In addition, the captured kanamycin was released for binding with the new aptamer, which resulted in the formation of a binding-hydrolysis-release cycle with the aid of Exo I. Under optimal conditions, this µPAD exhibited sensitive and multipath detection of kanamycin at concentrations as low as 1.26 × 10−14 M with a wide range of 10−13–10−7 M. Furthermore, satisfactory results were achieved for analysing spiked kanamycin in milk and honey samples. This strategy is a very promising tool for monitoring antibiotics and evaluating the safety of animal-derived foods.

A fluorescent aptasensor for enzyme-free and sensitive detection of kanamycin based on entropy-driven strand displacement reaction

BackgroundKanamycin is an antibiotic that can easily cause adverse side effects if used improperly. Due to the extremely low concentrations of kanamycin in food, quantitative detection of kanamycin becomes a challenge. As one of the DNA self-assembly strategies, entropy-driven strand displacement reaction (EDSDR) does not require enzymes or hairpins to participate in the reaction, which greatly reduces the instability of detection results. Therefore, it is a very beneficial attempt to construct a highly sensitive and specific fluorescence detection method based on EDSDR that can detect kanamycin easily and quickly while ensuring that the results are effective and stable. ResultsWe created an enzyme-free fluorescent aptamer sensor with high specificity and sensitivity for detecting kanamycin in milk by taking advantage of EDSDR and the high specific binding between the target and its aptamer. The specific binding can result in the release of the promoter chain, which then sets off the pre-planned EDSDR cycle. Fluorescent label modification on DNA combined with the fluorescence quenching-recovery mechanism gives the sensor impressive fluorescence response capabilities. The research results showed that within the concentration range of 0.1 nM–50 nM, there was a good relationship between the fluorescence intensity of the solution and the concentration of kanamycin. Specificity experiments and actual sample detection experiments confirmed that the biosensor could achieve highly sensitive and specific detection of trace amounts of kanamycin in food, with a detection limit of 0.053 nM (S/N = 3). SignificanceTo our knowledge, this is the first strategy to combine EDSDR with fluorescence to detect kanamycin in food. Accurate results can be obtained in as little as 90 min with no enzymes or hairpins involved in the reaction. Furthermore, our enzyme-free biosensing method is straightforward, highly sensitive, and extremely specific. It has many possible applications, including monitoring antibiotic residues and food safety.

A novel self-enhanced ECL-RET aptasensor based on the bimetallic MOFs with homogeneous catalytic sites for kanamycin detection

The inappropriate use of antibiotics undoubtedly poses a potential threat to public health, creating an increasing need to develop highly sensitive tests. In this study, we designed a new type of porphyrin metal-organic frameworks (Fe TCPP(Zn) MOFs) with homogeneous catalytic sites. The ferric-based metal ligands of Fe TCPP(Zn) MOFs acted as co-reaction accelerators, which effectively improved the conversion efficiency of H2O2 on the surface of MOFs, then increased the concentration of •OH surrounding porphyrin molecules to achieve self-enhanced electrochemiluminescence (ECL). Based on this, an aptasensor for the specific detection of kanamycin (KAN) in food and environmental water samples was constructed in combination with resonance energy transform (RET), in which Fe TCPP(Zn) MOFs were used as luminescence donor and AuNPs were used as acceptor. Under the best conditions, there was a good linear relationship between the ECL intensity and the logarithm of KAN concentration with a detection limit of 0.28 fM in the range of 1.0 × 10−7–1.0 × 10−13 M, demonstrating satisfactory selectivity and stability. At the same time, the complexity of the detection environment was reduced, which further realized the reliable analysis of KAN in milk, honey and pond water. Overall, this innovative self-enhanced ECL strategy provides a novel approach for constructing efficient ECL systems in MOFs, and also extends the application of MOFs to the analysis and detection of trace antibiotics in food and the environment.

Biomineralization–powered integrated immunoprobe and its application in Immunochromatographic assay

Immunochromatographic assay (ICA) has attracted widespread attention owing to its advantages of economy, simplicity, and rapidity. However, the synthesis of immunoprobes is still limited by complicated design ideas and multistep operations from preparing nanoparticles to conjugating monoclonal antibodies (mAb) onto nanoparticles. Inspired by the biomineralization of zeolitic imidazolate framework-8 (ZIF-8), we proposed a strategy for the rapid synthesis of an integrated immunoprobe (ZIF-8@QDs-mAb), achieving a one-step integration with strong fluorescent signal output capability and specific recognition ability. In addition, different fluorescent colors of ZIF-8@QDs-mAb were generated by doping red and green quantum dots (QDs) in various ratios. With a smart detection platform, the developed ZIF-8@QDs-mAb-based multiplex ICA (ZIF-8@QDs-mAb-mICA) achieved the on-site quantitative detection of enrofloxacin, sulfamethazine, and kanamycin in milk within 15 min, with the limit of detection (LOD) of 0.052, 0.186 and 0.216 ng mL−1, which were 5.69, 2.20 and 4.40 times higher than that of gold nanoparticles-based mICA, respectively. The quantitative detection of alpha-fetoprotein and human chorionic gonadotropin was also achieved with LOD of 0.516 ng mL−1 and 0.225 mIU mL−1, respectively, which verified the universality of the strategy. This work provides a novel idea for the design of an efficient integrated immunoprobe and has broad application prospects in ICA.

Construction of Liquid Crystal-Based Sensors Using Enzyme-Linked Dual-Functional Nucleic Acid on Magnetic Beads.

The development of liquid crystal (LC)-based sensors with superior performances such as high portability, excellent stability, great convenience, and remarkable sensitivity is highly demanded. This work proposes a new strategy for constructing the LC-based sensor using enzyme-linked dual-functional nucleic acid (d-FNA) on magnetic beads (MBs). The detection of kanamycin (KA) is demonstrated as a model. Acetylcholinesterase (AChE) is assembled onto the KA aptamer-modified MBs with a d-FNA strand that consists of an AChE aptamer and the complementary sequence of a KA aptamer. As the specific recognition of KA by its aptamer triggers the release of AChE from the MBs, the myristoylcholine (Myr) solution after incubation with the MBs causes the black image of the LCs due to the formation of the Myr monolayer at the aqueous/LC interface. Otherwise, in the absence of KA, AChE is still decorated on the MBs and causes the hydrolysis of Myr. Therefore, a bright image of LCs is obtained. The detection of KA is successfully achieved with a lower detection limit of 48.1 pg/mL. In addition, a thin polydimethylsiloxane (PDMS) layer-coated glass and a portable optical device are used to improve the stability and portability of the LC-based sensor to advance potential commercial applications. Furthermore, the detection of KA in milk with a portable device is demonstrated, showing the potential of the proposed enzyme-linked LC-based sensor.

A robust tag-free aptasensor for fluorescent detection of kanamycin assisted by signal intensification potency of rolling circle amplification

Rolling circle amplification (RCA) process as an excellent DNA amplifier strategy possesses the merits of high performance and easy operation. In this research, a sensitive RCA-based fluorescent aptasensor was fabricated for the detection of kanamycin residues in food. The aptasensing approach consisted of two main steps; immobilization of biotinylated kanamycin aptamer on streptavidin magnetic beads (SMB) and separation of free complementary strands (CS) from the SMB-aptamer/kanamycin at the first step. For the second step, RCA procedure was applied as signal magnifier and SYBR Green was added as fluorescent indicator dye. The linear relation between the aptasensor response and kanamycin concentration was obtained from 5 nM to 100 nM with the detection limit of 1.93 nM (S/N = 3). The aptasensor displayed satisfactory selectivity among other antibiotics. The developed aptasensor is reliable for monitoring kanamycin in milk as a common foodstuff.

A molecularly imprinted electrochemical sensor for specific and ultrasensitive determination of an aminoglycoside drug: the role of copper ions in the determination.

Herein, a molecularly imprinted polymer (MIP) was fabricated for specific sensing of an aminoglycoside e.g. kanamycin (KANA). Carbon paste modified with a MIP specific to Cu2+-KANA was first introduced. Copper (Cu2+) as a metal ion was used as a signal tracer and an amplifier, producing a current response measured by differential pulse voltammetry (DPV). Introducing the aminoglycoside drug into the solution containing Cu2+ did not affect the current response of the NIP/CPE. Under the optimum conditions, the as-fabricated sensor exhibited an increase in the current response in the range of 0.55-550 nM with a good limit of detection (LOD, S/N = 3) of 161 pM. The sensor exhibited many advantages including high sensitivity and selectivity, good stability and reproducibility, and cost-effectiveness. Moreover, it was successfully applied for the determination of KANA in milk and honey samples with RSD % not more than 3.3%, suggesting the reliability of the as-designed sensor.

Target-mediated competitive hybridization of hairpin probes for kanamycin detection based on exonuclease III cleavage and DNAzyme catalysis.

Based on aptamer recognition and target-mediated competitive hybridization of hairpin probes, we developed a fluorescence sensor for kanamycin (KAN) detection. The aptamer and KAN binding will open hairpin H1 to release the trigger DNA fragment, which can initiate the competitive hybridization between hairpins H2 and H3. Then, exonuclease III (Exo III) can cleave H2 and H3 to produce numerous DNA3 and DNA4. Through the synergetic hybridization among DNA1, DNA2, DNA3, and DNA4, an active Mg2+-DNAzyme can be formed. The cleavage reaction toward FAM-BHQ-modified DNA2 will produce a high fluorescence signal for KAN assay. Through Exo III-guided cleavage and Mg2+-DNAzyme-based catalysis, the sensor exhibits high sensitivity, with a detection limit of 3.1 fM. This method is robust and has been applied to the detection of KAN in milk and water samples with good accuracy and reliability. Our developed fluorescence sensor exhibits the advantages of simple operation, high sensitivity, and good robustness, which are beneficial for KAN detection in food samples.

Gold nanoparticle‐carbon nanotube nanohybrids with peroxidase‐like activity for the highly‐sensitive immunoassay of kanamycin in milk

SummaryOwing to the increasing incidences of antibiotic residues being found in foods of animal‐origin, rapid and reliable screening methods for detecting these residues are urgently required. This study aimed to develop a robust and ultrasensitive colorimetric immunoassay based on nanohybrids for the rapid screening of kanamycin (KAN) residues in milk. The HAuCl4 solution was directly reduced on the multiwalled carbon nanotubes (MWCNTs) using a one‐step synthesis method to obtain the Au/MWCNTs nanohybrids. The Au/MWCNTs exhibited mimetic peroxidase activity and higher affinities for the TMB and H2O2 compared with horseradish peroxidase and other nanohybrids. A direct competitive enzyme‐linked immunosorbent assay (dcELISA) based on Au/MWCNTs was developed and employed for KAN detection in milk samples under optimised conditions. The dcELISA showed high sensitivity toward KAN residues, with a detection limit of 11.2 pg/mL. Moreover, this novel immunoassay displayed high precision and accuracy in milk samples, with a recovery rate ranging from 94.3 to 124.5% and a coefficient variation from 7.8 to 11.3%. Eight real milk samples were found to contain a KAN concentration in the range of ND–0.26 ng/mL. Therefore, this dcELISA based on the Au/MWCNTs nanohybrid has promising potential for applications in food monitoring and quality control.

Construction of a dual-model aptasensor based on G-quadruplexes generated via rolling circle amplification for visual/sensitive detection of kanamycin

A dual-model colorimetric and electrochemical aptasensor was designed using a large number of G-quadruplexes generated by rolling circle amplification (RCA). Specific binding between target and aptamer during RCA yielded large numbers of G-quadruplexes. A colorimetric sensor was fabricated based on the interaction between the G-quadruplex and hemin, which altered the 3,3′,5,5′-Tetramethylbenzidine (TMB)-catalyzed color reaction and facilitated the visual and semi-quantitative detection of kanamycin. An electrochemical sensor was constructed based on the strong interaction between the G-quadruplex and the methylene blue electrical signal molecule. Combining nanocomposites multi-walled carbon nanotubes-chitosan/gold nanoparticles (MWCNTs-CS/AuNPs) and RCA realized double-amplified electrochemical signals. Under optimized conditions, a linear relationship was obtained as the logarithm of different concentrations of kanamycin (KAN). The colorimetric aptasensor had a linear range of 1 × 102 nM to 1 × 103 nM with a detection limit of 1.949 nM. The electrochemical aptasensor had wider a linear range from 1 × 10−3 nM to 2.5 × 103 nM and a lower detection limit of 0.333 pM. The sensor combined the advantages of simple colorimetric visualization with the ultra-precision of electrochemical methods. Aptasensor showed good specificity and prevented interference. Furthermore, the prepared dual-model aptasensor facilitated the practical monitoring of KAN in milk.

Fluorescent aptasensor based on DNA-AgNCs emitting in the visible red wavelength range for detection of kanamycin in milk

Fluorescence sensors detect veterinary drug residues in milk, which are usually interfered with by the complex milk matrix. The specific DNA template can produce DNA stabilized silver nanoclusters (DNA-AgNCs) emitting in the visible red wavelength range. This will reduce the fluorescence interference of milk by avoiding the fluorescence signal generated by the inherent component of milk in the relatively short wavelength range. Furthermore, the red fluorescence has relatively high penetration, which can also reduce the impact of interfering substances. Here, on the basis of fluorescence resonance energy transfer (FRET), we designed a fluorescent aptasensor using DNA-AgNCs and gold nanoparticles (AuNPs) to detect kanamycin (KAN) residue in milk. Due to electrostatic interaction, DNA adsorbs on the AuNPs. The decrease in the distance between DNA-AgNCs and AuNPs generates FRET, which causes the fluorescence of DNA-AgNCs to be quenched. When KAN is added, the aptamer and KAN can specifically bind with high affinity, resulting in a weakening of the electrostatic interaction between DNA-AgNCs and AuNPs. This results in a decrease in FRET between DNA-AgNCs and AuNPs, and recovery of the fluorescent signal intensity of DNA-AgNCs. The designed sensor has satisfactory specificity and sensitivity for the detection of KAN residues. The applied strategy showed the limit of KAN detection to be as low as 22.6 nM. Moreover, this work provides a way for reducing the interference of the milk background fluorescence signal in the fluorescence sensor and has broad application prospects.

A label-free and enzyme-free fluorescent aptasensor for amplified detection of kanamycin in milk sample based on target-triggered catalytic hairpin assembly

Kanamycin residues in foods can cause serious adverse reactions in human body, and the accurate and sensitive detection of kanamycin is of great significance to ensure human health. In this work, we constructed a label-free and enzyme-free fluorescent aptasensor for quantifying kanamycin in milk based on target-triggered catalytic hairpin assembly. First, we designed an aptamer probe that contained an aptamer unit for recognizing kanamycin, a trigger unit for triggering catalytic hairpin assembly and a suppression unit for ensuring the stability of aptamer probe. In the initial state, the trigger unit was closed by suppression unit and inactive. After the aptamer unit recognized and bound to kanamycin, a free trigger unit was released to trigger the cycle hybridization reactions between hairpin probe 1 and hairpin probe 2, generating G-rich complexes and realizing enzyme-free amplification detection. Then, N-methylmesoporphyrin IX as signal molecules were combined with G-rich complexes to generate a significant fluorescent signal, which realized label-free detection. Thus, the aptasensor provided a well sensitivity for kanamycin with a detection limit of 0.26 ng/mL. And it possessed well selectivity and could distinguish kanamycin from its analogues, which stemmed from the specific recognition between kanamycin and aptamer. The aptasensor had great potential application value in the field of ensuring food safety.

Reduced Graphene Oxide/Poly(2-Aminopyridine) Modified Molecularly Imprinted Glassy Carbon Electrode (GCE) for the Determination of Kanamycin in Milk and Pork by Differential Pulse Voltammetry (DPV)

Kanamycin (KAN) is a widely used aminoglycoside antibiotic that has attracted attention due to its presence in food and the environment. In order to obtain a simple, rapid, and sensitive method for kanamycin, an electrochemical sensor was fabricated by successively modifying a glassy carbon electrode (GCE) with reduced graphene oxide (rGO), poly(2-aminopyridine) (pAP) film, and a KAN molecularly imprinted membrane (KAN-MIM) that was prepared by electroreduction of graphene oxide and the electropolymerization of 2-aminopyridine and dopamine. The morphology and electrochemical parameters were characterized for the sensor designated by KAN-MIM/pAP/rGO/GCE. As a result of the amplification of the modified electrode, excellent analytical performance was obtained on the bases of sensitivity, selectivity, repeatability, and stability. The linear range and limit of detection for kanamycin were from 0.02 to 250.0 μmol·L−1 and 7.0 nmol·L−1, respectively. The sensor was employed to determine KAN in pork and milk with recoveries from 89.2% to 109.0% and a relative standard deviation less than 6.0%.

A competitive colorimetric aptasensor for simple and sensitive detection of kanamycin based on terminal deoxynucleotidyl transferase-mediated signal amplification strategy

We developed a rapid and sensitive colorimetric biosensor based on competitive recognition between kanamycin (KAN), magnetic beads-kanamycin (MBs-KAN) and aptamer and terminal deoxynucleotidyl transferase (TdT)-mediated signal amplification strategy. In the absence of KAN, aptamers recognize MBs-KAN. TdT can amplify oligonucleotides to the 3′-OH ends of aptamers, with biotin-dUTP being embedded in the long single stranded DNA (ssDNA). Then the assay produced visual readout due to the horseradish peroxidase (HRP)-catalyzed color change of the substrate after the linkage between biotin and streptavidin (SA)-HRP. In the presence of KAN, however, aptamers tend to bind free KAN rather than MBs-KAN. In this case, aptamers are isolated by magnetic separation, resulting in the failure of signal amplification and catalytic signals. This competitive colorimetric sensor showed excellent selectivity toward KAN with the limit of detection (LOD) as low as 9 pM. And recovery values were between 93.8 and 107.8% when spiked KAN in milk and honey samples.

Signal-off photoelectrochemical aptasensor for kanamycin: Strand displacement reaction combines p-n competition

A“signal-off” photoelectrochemical aptasensor based on p-n type semiconductor competitive quenching effect and strand displacement reaction was constructed for the determination of kanamycin. Au NPs@MgIn2S4-graphene composite was used as n-type photoactive semiconductor material. In the presence of the kanamycin, strand displacement reaction was triggered and the p-type CuInS2 quantum dots labeled aptamer was introduced on the Au NPs@MgIn2S4-graphene surface. The CuInS2 quantum dots can competitive consume the electron donors (AA) and light energy of the PEC system, thus quenched the anodic photocurrent of Au NPs@MgIn2S4-graphene. The photocurrent decreased with the increase of kanamycin concentration. The linear range of kanamycin was 1.0 pM–10 μM, and the detection limit was 1.7 pM. In addition, the method can be used for the determination of kanamycin in milk and honey.

Aptamer act as fluorescence switching of bovine serum albumin stabilized gold nanoclusters for ultrasensitive detection of kanamycin in milk

We developed a fluorescent switching based on bovine serum albumin stabilized gold nanoclusters (BSA-AuNCs) and kanamycin (Kana) aptamer to detect Kana. Red fluorescence of BSA-AuNCs was turn off when Kana aptamer was assembled on the surface of BSA-AuNCs. However, after adding Kana, the specific aptamer detached from the surface of the BSA-AuNCs and formed the complex of aptamer-kanamycin, then the red fluorescence of BSA-AuNCs was turn on. The fluorescence intensity of BSA-AuNCs can be mediated by the amount of Kana aptamer. A good linear response for Kana was obtained in the concentration range 0.04 nM to 7.0 nM. The assay was used to detect Kana in milk matrix, and the accuracy and recovery of the method were satisfied. It is worth noting that the aptamer mediated BSA-AuNCs fluorescent switching was simple and easy to fabricate, which can provide a novel assay for the detection of small molecules.

Functionalized Persistent Luminescence Nanoparticle-Based Aptasensor for Autofluorescence-free Determination of Kanamycin in Food Samples.

Selective and sensitive determination of trace kanamycin in complex food samples is of great importance for food safety because of its high toxicity. Here, we report a sensitive and autofluorescence-free persistent luminescence (PL) aptasensor for selective, sensitive, and autofluorescence-free determination of kanamycin in food samples. The aptamer for kanamycin was first conjugated onto the surface of magnetic nanoparticles Fe3O4 to serve as the recognition unit as well as the separation element, while the PL nanoparticles ZnGa2O4:Cr (PLNPs) were functionalized with the aptamer complementary DNA (cDNA) as the PL signal. The PL aptasensor consisted of the aptamer-conjugated MNPs (MNPs-apt) and cDNA-functionalized PLNPs (PLNPs-cDNA) and combined the merits of the long-lasting luminescence of PLNPs, the magnetic separation ability of MNPs as well as the selectivity of the aptamer, offering a promising approach for autofluorescence-free determination of kanamycin in food samples. The proposed aptasensor showed excellent linearity in the range from 1 pg mL-1 to 5 ng mL-1 with a limit of detection of 0.32 pg mL-1. The precision for 11 replicate determinations of 100 pg mL-1 kanamycin was 3.1% (relative standard deviation). The developed aptasensor was applied for the determination of kanamycin in milk and honey samples with the recoveries of 95.4-106.3%. The proposed aptasensor is easily extendable to other analytes by simply replacing the aptamer, showing great potential as a universal aptasensor platform for selective, sensitive, and autofluorescence-free detection of hazardous analytes in food samples.

Aptamer biorecognition-triggered hairpin switch and nicking enzyme assisted signal amplification for ultrasensitive colorimetric bioassay of kanamycin in milk

A colorimetric aptasensing strategy for detection of kanamycin was designed based on aptamer biorecognition and signal amplification assisted by nicking enzyme. The aptamer of kanamycin was designed to be contained in the metastable state hairpin DNA. The target DNA as recycling DNA was located in the loop of hairpin DNA. The presence of kanamycin stimulates the continuous actions, including specific recognition of the aptamer to kanamycin, the hybridization between target DNA and signal probe, the cleavage function of nicking enzyme. The actions induced accumulation of numerous free short sequences modified by platinum nanoparticles (PtNPs), which can catalyze the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB)-H2O2 to produce a colorimetric response. The aptasensor exhibited good selectivity and sensitivity for kanamycin in milk with a detection limit as low as 0.2 pg·mL−1. In addition, the proposed assay is potentially to be extended for other antibiotics detection in foods by adapting the corresponding aptamer sequence.