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Öğe Development of molecularly imprinted polymer-based optical sensor for the sensitive penicillin g detection in milk(WILEY-V C H VERLAG GMBH, 2021) Safran, Volkan; Göktürk, Ilgım; Bakhshpour, Monireh; Yılmaz, Fatma; Denizli, AdilIn this study, selective and sensitive Penicillin G (PEN-G) antibiotic detection from both aqueous solution and milk samples using molecular imprinting technique was performed by surface plasmon resonance sensor. For this purpose, PEN-G imprinted poly(2-Hydroxyethyl methacrylate-N-methacroyl-(L)-cysteine methyl ester-gold nanoparticles-N-methacryloyl-L-phenylalanine methyl ester (MIP-AuNPs) nanosensor was prepared. Control experiments were carried out via the nanosensor without the addition of AuNPs (MIP) to examine the effect of gold nanoparticles (AuNPs) incorporated to increase the surface plasmon resonance signal response. Moreover, to evaluate the imprinting efficiency, non-imprinted (NIP-AuNPs) nanosensor was designed using the same polymerization recipe except the addition of the PEN-G molecule. Characterization studies of MIP, MIP-AuNPs and NIP-AuNPs nanosensors were performed with FTIR-ATR spectrophotometer. Also, MIP-AuNPs and NIP-AuNPs nanosensors were characterized by atomic force microscopy, ellipsometer and contact angle measurements. Imprinting efficiency (I.F: 7.83) for the MIP-AuNPs nanosensor was determined by comparing it with the NIP-AuNPs nanosensor. The MIP-AuNPs nanosensor was 9.87 times more selective for the target PEN-G molecule than amoxicillin, and 16.78-times than ampicillin. In addition, the amount of PEN-G in milk selected as a real sample was measured by spiking 5 ppb PEN-G into the milk.Öğe Novel QCM and SPR sensors based on molecular imprinting for highly sensitive and selective detection of 2,4-dichlorophenoxyacetic acid in apple samples(Elsevier Science Bv, 2019) Çakır, Oğuz; Bakhshpour, Monireh; Yılmaz, Fatma; Baysal, ZübeydeThis study aims to develop molecularly imprinted based quartz crystal microbalance (QCM) and surface plasmon resonance (SPR) sensors for highly sensitive and selective detection of 2,4-dichlorophenoxyacetic acid (2,4-D) and to determine their accuracy and precision by liquid chromatography-tandem mass spectrometry (LC-MS/MS) as a reference technique. Here, we synthesized non-imprinted (NIP) and 2,4-D-imprinted (MIP) [ethylene glycol dimetacrylate-N-metacryloyl-(L)-tryptophan methyl ester-p(EGDMA-MATrp)] polymeric nanofilms by using molecular imprinting technique. MIP and NIP nanofilms were characterized by fourier transform infrared spectroscopy attenuated total reflectance (FTIR-ATR), atomic force microscope (AFM), contact angle and ellipsometer measurements. The molecular imprinting procedures were successfully carried out and it was found that the prepared polymeric surfaces were highly desirable for sensitive recognition by QCM and SPR sensors. Competitive experiments for the sensors revealed that MW nanofilms were found to show more sensitivity and selectivity than NIP ones. The sensor responses have a good linear relationship with 2,4-D concentrations in the range of 0.23-8.0 nM with a limit of detection at 20.17 ng/L for QCM and 24.57 ng/L for SPR sensors. In conclusion, both QCM and SPR sensor systems showed good accuracy and precision, with recovery percentages between 90 and 92% and 87-93%, respectively. Furthermore, they have a fast response time, reusability, high selectivity and sensitivity and low limit of detection.Öğe Pestisit tayini için nanopartiküllerle duyarlılığı arttırılmış moleküler baskılama temelli yüzey plazmon rezonans sensörlerin hazırlanması(2018) Çakır, Oğuz; Bakhshpour, Monireh; Yılmaz, Fatma; Baysal, ZübeydePestisitler yıllardır tarım alanlarında kullanılmaktadır. Ancak bu yaygın kullanım, bilimsel ve endüstriyel topluluklarda pestisitlerin uzun vadeli insan sağlığı riskleri üzerine bilinen toksisitelerinden dolayı endişeyi arttırmıştır. Böylelikle pestisitlerin tayin edilmesi, hem insanlar üzerinde artan toksik etkilerinden hem de kullanımının kontrol altına alınmasından dolayı büyük bir öneme sahiptir. Bu çalışmada, seçici, hassas, hızlı ve gerçek zamanlı klorpirifos tayini için ilk olarak, poli[etilenglikol dimetakrilat-N-metakriloil-(l)-triptofan metil ester poly(EGDMA-MATrp) nanopartikülleri hazırlandı ve zeta sizer ile karakterize edildi. Ardından, klorpirifos baskılı SPR nanosensör hazırlanarak atomik kuvvet mikroskobu (AFM) ve temas açısı ölçümleri ile karakterize edildi. Kalınlık ölçümleri ve AFM görüntüleri, nanopartiküllerden oluşan ince filmlerin hemen hemen tek tabakalı olduğunu gösterdi. Baskılanmış ve baskılanmamış nanosensörlerin klorpirifos tayin duyarlılığı 0.015-2.9 nM aralığında klorpirifos çözeltileri ile araştırıldı. Baskılanmış nanopartiküllerin, baskılanmamışlara göre daha fazla duyarlılık gösterdiği belirlendi. Langmuir adsorpsiyon modeli, bu afinite sistemi için en uygun model olarak belirlendi. Klorpirifos baskılanmış nanopartiküllerin seçiciliğini göstermek için 2.9 nM derişimindeki klorpirifos, diazinon ve parationun yarışmalı adsorpsiyonu araştırıldı. Sonuç olarak, SPR nanosensörlerin hızlı yanıt, kullanım kolaylığı, hassasiyet, seçicilik ve gerçek zamanlı ölçüm alınabilme özelliğinden dolayı pestisit analizleri için alternatif bir yöntem olarak kullanılma potansiyeline sahip olduğu görüldü.Öğe Selective detection of penicillin g antibiotic in milk by molecularly imprinted polymer-based plasmonic SPR sensor(MDPI, 2021) Bakhshpour, Monireh; Göktürk, Ilgım; Bereli, Nilay; Yılmaz, Fatma; Denizli, AdilMolecularly imprinted polymer-based surface plasmon resonance sensor prepared using silver nanoparticles was designed for the selective recognition of Penicillin G (PEN-G) antibiotic from both aqueous solution and milk sample. PEN-G imprinted sensors (NpMIPs) SPR sensor was fabricated using poly (2-hydroxyethyl methacrylate-N-methacroyl-(L)-cysteine methyl ester)-silver nanoparticles-N-methacryloyl-L-phenylalanine methyl ester polymer by embedding silver nanoparticles (AgNPs) into the polymeric film structure. In addition, a non-imprinted (NpNIPs) SPR sensor was prepared by utilizing the same polymerization recipe without addition of the PEN-G template molecule to evaluate the imprinting effect. FTIR-ATR spectrophotometer, ellipsometer, contact angle measurements were used for the characterization of NpMIPs SPR sensors. The linear concentration range of 0.01-10 ng/mL PEN-G was studied for kinetic analyses. The augmenting effect of AgNPs used to increase the surface plasmon resonance signal response was examined using polymer-based PEN-G imprinted (MIPs) sensor without the addition of AgNPs. The antibiotic amount present in milk chosen as a real sample was measured by spiking PEN-G into the milk. According to the Scatchard, Langmuir, Freundlich and Langmuir-Freundlich adsorption models, the interaction mechanism was estimated to be compatible with the Langmuir model.Öğe Selective dopamine detection by SPR sensor signal amplification using gold nanoparticles(ROYAL SOC CHEMISTRY, 2021) Türkmen, Deniz; Bakhshpour, Monireh; Göktürk, Ilgım; Aşır, Süleyman; Yılmaz, FatmaIn this study, selective and sensitive detection of the neurotransmitter dopamine (DA) in both aqueous solution and biological samples was performed using a surface plasmon resonance (SPR) sensor based on a molecular imprinting technique. For this, dopamine-imprinted poly(2-hydroxyethyl methacrylate-N-methacroyl-(l)-cysteine methyl ester-gold nanoparticles-N-methacryloyl-l-phenylalanine methyl ester) [PHEMAC-AuNPs/MAPADA] nanoparticles were prepared. Furthermore, to evaluate the imprinting efficiency, non-imprinted [PHEMAC-AuNPs/MAPA] nanoparticles were designed using the same polymerization procedure except for the addition of dopamine molecules. To examine the effect of incorporating AuNPs to increase the SPR signal response, control experiments were carried out via the SPR biosensor produced using [PHEMAC/MAPADA] nanoparticles prepared without the addition of AuNPs. Characterization studies of dopamine- + imprinted [PHEMAC-AuNPs/MAPADA] and non-imprinted [PHEMAC-AuNPs/MAPA] nanoparticles was performed with a zetasizer and an FTIR-ATR spectrophotometer. In addition, dopamine-imprinted [PHEMAC-AuNPs/MAPADA] and non-imprinted [PHEMAC-AuNPs/MAPADA] SPR sensors were characterized by ellipsometer and contact angle measurements. The high imprinting efficiency (I.F: 9.67) of the dopamine-imprinted [PHEMAC-AuNPs/MAPADA] SPR sensor was determined by comparing it with the non-imprinted [PHEMAC-AuNPs/MAPA] SPR sensor. A good linear relationship was obtained in the 0.01-0.5 ppb concentration range with correlation coefficients of 0.9818 and 0.9819, respectively. The dopamine-imprinted [PHEMAC-AuNPs/MAPADA] SPR sensor was 5.53 and 4.59 times more selective for the target molecule dopamine than for epinephrine (EP) and norepinephrine (NE), respectively. The repeatability of the [PHEMAC-AuNPs/MAPADA] SPR sensor was assessed with a 0.5 ppb dopamine solution, with the percent relative standard deviation of the intra-assays (RSD) being less than 1.7%, indicating negligible loss of dopamine sensing capability after four adsorption-desorption cycles with the same sensor.Öğe Sensitive and selective detection of amitrole based on molecularly imprinted nanosensor(Wiley, 2021) Çakır, Oğuz; Bakhshpour, Monireh; Göktürk, Ilgım; Yılmaz, Fatma; Baysal, ZübeydeHerein, a surface plasmon resonance (SPR)-based nanosensor was fabricated usingmolecular imprinting technique for the selective and sensitive detection of amitrole, acommonly used highly toxic pesticide. For this purpose, polymeric nanofilms involvingN-methacryloyl-L-tryptophan methyl ester and ethylene glycol dimethacrylate whichare functional monomer and cross-linker, respectively, were prepared on the SPR chipssurface via the ultravoilet polymerization method. The nanofilms were characterized byseveral techniques such as ellipsometry, Fourier transform infrared-attenuated totalreflection, atomic force microscope and contact angle measurements. The kinetic ana-lyses for amitrole detection were examined through amitrole-imprinted and non-imprinted SPR sensor chips. The developed imprinted sensor showed high selectivity tothe amitrole molecule than similar molecules and a good linear relationship for the0.06-11.90 nM concentration range with a low limit of detection value of 0.037 nM.The high imprinting efficiency (I.F: 62.38) of the amitrole-imprinted SPR sensor wasdetermined by comparing it with the non-imprinted SPR sensor. The most suitablemodel of this sensor is the Langmuir adsorption model. To statistically assess the reus-ability of the sensor, intraday experiments were tested three times with five replicates.The relative standard deviation% value less than <1.5 indicates high reproducibility forboth sensor production and reproducibility of the method. The prepared sensor wasalso applied efficiently for the selective detection of the amitrole in spiked samples pre-pared from vegetables to evaluate the matrix effect. As a result, amitrole-imprinted SPRsensors have been estimated to be highly selective, fast responsive, easy to use, reus-able and sensitive in detecting amitrole in both natural source and aqueous solutions.Label-free amitrole detection was performed by an aminoacid-based SPR sensor fabri-cated without the need for complex coupling processes.Öğe Sensor applications for detection in agricultural products, foods, and water(Springer International Publishing, 2022) Bakhshpour, Monireh; Göktürk, Ilgim; Gür, Sinem Diken; Yilmaz, Fatma; Denizli, AdilPesticides are used to control pests that can destroy or reduce food production. Therefore, they are an important management tool to increase agricultural crop yield and reduce post-harvest losses, especially in a world facing hunger and famine. Although pesticides are useful in food production, they may have harmful effects such as being permanent in the environment and accumulating in living organisms, since they cannot be biodegradable. As pesticides have been widely used in agriculture for decades, concerns have been raised due to their known toxicity to human health. Thus, the determination of pesticides is of great importance due to both their increasing toxic effects on human health and the control of their use. Analytical technology methods developed using sensors are a wide-ranging field that affects industrial sectors such as medicine, health, food, agriculture, environment, and water. This chapter covers sensors and biosensors that have been developed in recent years to identify analytes sensitive to water pollution, especially used in food safety. Also, the basic principles of sensor systems used in the analysis of pollutants are mentioned. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2022.
