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Comparison of polyacrylonitrile-and polypyrrole-based electrochemical sensors for detection of propamocarb in food samples
(Turkish Chemical Society, 2022) Karakuş, Selcan; Taşaltın, Cihat; Gürol, İlke; Akkurt, Barbaros; Baytemir, Gülsen; Taşaltın, Nevin
Food safety is a crucial issue; all countries have struggled against pesticides for years. In this study, Polypyrrole (PPy)- and Polyacrylonitrile (PAN)-based non-enzymatic electrochemical sensors were investigated to detect the pesticide propamocarb (PM) in food samples. Under the experimental conditions, the proposed strategy exhibited a high selectivity of the disposable PPy-based and PANbased sensors for the determination of propamocarb pesticide in the concentration of 1 ?M with a rapid detection within 1 min at pH 7.4 and 25 °C. We demonstrated the detection of PM residues on cucumber and tomato samples with good electrochemical performances towards the real-time usability on real food samples. PAN-based non-enzymatic electrochemical sensor has good sensitivity, higher selectivity, and stability than PPy-based non-enzymatic electrochemical sensor. The prepared PAN-based nonenzymatic electrochemical sensor is a potential candidate to be used in devices which perform food safety in agricultural products.
Copper phthalocyanine-borophene nanocomposite-based non-enzymatic electrochemical urea biosensor
(Springer Heidelberg, 2022) Güngör, Saliha; Taşaltın, Cihat; Gurol, Ilke; Baytemir, Gülsen; Karakuş, Selcan; Taşaltın, Nevin
Highly sensitive detection of urea is important and necessary in a wide variety of areas such as clinical diagnostics, environmental monitoring, and food safety applications. Herein, we demonstrated the fabrication of the sonochemical synthesized copper phthalocyanine (CuPc)-borophene nanocomposites-based non-enzymatic electrochemical biosensor for the urea detection at room temperature. The prepared CuPc, borophene, and CuPc-borophene nanocomposite were characterized using different techniques such as scanning electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and Raman spectroscopy. With the surface and chemical advantages of CuPc-borophene nanocomposite, urea detection performances of the CuPc-borophene nanocomposite-based biosensors exhibited a high selectivity in many matrices such as glucose, fructose, lactose, and maltose, even in highly complex isotonic solutions containing competitive ions at room temperature. CuPc-borophene nanocomposite-based sensor exhibited higher sensitivity of 10.43 mu A/mMcm(2) against (250-1000) mu M with a detection limit of 0.05 mu M in voltammetric cycle of 60 s due to high charge transport advantages of borophene additive. Experimental results revealed that the CuPc-borophene nanocomposite-based non-enzymatic electrochemical biosensor was a sensitive, stable, rapid, portable, and low-cost. Furthermore, the biosensor is a promising candidate for urea electrochemical analysis in a complex aqueous medium for biomedical applications.
Cubic-shaped corylus colurna extract coated Cu2O nanoparticles-based smartphone biosensor for the detection of ascorbic acid in real food samples
(Elsevier Sci Ltd, 2023) Karakuş, Selcan; Özbas, Fatih; Baytemir, Gülsen; Taşaltın, Nevin
Ascorbic acid (AA) is a highly water-soluble organic chemical compound and plays a significant role in human metabolism. For the purpose of food quality monitoring, this study focuses on the development of a smartphone-integrated colorimetric and non-enzymatic electrochemical Corylus Colurna (CC) extract-Cu2O nanoparticles (Cu2O NPs) biosensor to detect AA in real food samples. The characterization of the CC-Cu2O NPs was deter-mined using SEM, SEM/EDX, HRTEM, XRD, FTIR, XPS, TGA, and DSC. The CC-Cu2O NPs are cubic in shape with an approximate size of 10 nm. According to electrochemical results, the oxidation of AA at the modified electrode exhibited a LOD of 27.92 nmolL-1 in a wide concentration range of 0.55-22 mmolL-1. The fabricated digital CC-Cu2O NPs sensor successfully detected AA in food samples. This strategy provides a nanoplatform to determine the detection of AA in food samples.
Design of the polyacrylonitrile-reduced graphene oxide nanocomposite-based non-enzymatic electrochemical biosensor for glucose detection
(Springer, 2022) Karakuş, Selcan; Taşaltın, Cihat; Gurol, Like; Baytemir, Gülsen; Taşaltın, Nevin
With the advantages of developed electronic devices, various biosensor applications have become attractive issues with excellent electrochemical performances against biomarkers and molecules in biomedical applications. In this study, novel polyacrylonitrile (PAN)-reduced graphene oxide (rGO) nanocomposite-based non-enzymatic electrochemical biosensors were prepared to investigate the detection performance of the glucose. The PAN-rGO nanocomposite-based biosensor detected glucose with a high sensitivity and stability due to enhanced redox mechanism arising from rGO additive. PAN-rGO nanocomposite-based biosensor detected glucose in (0.75-12) mM with a high sensitivity of 49 mu AmM-1 cm(-2) (2.5 times higher than PAN-based sensor). Concentration-response graphs correlating the non-enzymatic electrochemical signal to glucose concentration revealed a low limit of detection (LOD) of 0.6 mM within 1-min voltammetric cycle. The selectivity results confirmed a significant preferential response of the proposed PAN-rGO nanocomposite-based biosensor for glucose against possible interfering compounds. The proposed PAN-rGO nanocomposite-based biosensor has a great potential to be used as a nanostructured platform for detection of glucose in phosphate-buffered saline (pH 7.4) solution with high sensitivity, selectivity, stability, reproducibility, and fast response properties.
Digital colorimetric and non?enzymatic biosensor with nanoarchitectonics of Lepidium meyenii?silver nanoparticles and cotton fabric: real?time monitoring of milk freshness
(Applied Physics A, 2022) Karakuş, Selcan; Baytemir, Gülsen; Taşaltın, Nevin
With advances in nanotechnology research, there is a growing interest in fabricating sensitive digital colorimetric biosensors with their excellent performance and selectivity for the detection of target analytes in sensor applications. Herein, a novel Lepidium meyenii polyphenol extract (PPE)/silver nanoparticles (Ag NPs) coated cotton fabric as a biosensor was developed as a sensitive smartphone-integrated colorimetric and non-enzymatic biosensor for real-time monitoring of milk freshness. The PPE–Ag NPs were characterized using diferent techniques such as SEM, HRTEM, FTIR, and AFM techniques. Furthermore, HRTEM images of the prepared PPE–Ag NPs were powered using an artifcial intelligence (AI) approach. The novel digital colorimetric PPE–Ag NPs coated cotton fabric biosensor exhibited an ultra-sensitive detection for H2O2 with a high coefcient correlation (R2=0.987) and low limit of detection (LOD) of 3.84 ?M in a wide concentration range of 0.5–5000 µM in the presence of interfering biomolecules such as ascorbic acid, urea, glucose, and lactose. The electrochemical response of the biosensor was proportional to the H2O2 concentration in a range of 40–800 µM with a low LOD of 33.52 nM. Consequently, the experimental results showed that it is a promising biosensor for the determination of H2O2 in intelligent food applications.
Energy storage performance of three-dimensional ta nanopillars based electrode for supercapacitors
(Elsevier, 2022) Taşaltın, Nevin; Taşaltın, Cihat; Karakuş, Selcan; Baytemir, Gülsen
In this study, Ta nanopillar array was prepared using Anodic aluminium oxide (AAO) nanotemplate assisted method. Ta nanopillars are approximately 80 nm in width and 150 nm in length. In electrochemical measurements, the electrons in the Ta nanopillars and ions in the H2SO4 electrolyte formed the electrical double layer supercapacitor (EDLC). The specific capacitance of the Ta nanopillar array electrode was 640 Fg -1. Ta nanopillararray electrode has 86% retention after 1000 cycles. The results reveal that the Ta nanopillar array-based electrode is a potential candidate electrode material for supercapacitors.
Highly Selective and Sensitive Non-enzymatic Glucose Biosensor Based on Polypyrrole-Borophene Nanocomposite
(2022) Baytemir, Gülsen
In this study, a non-enzymatic glucose sensor composed of two-dimensional (2D) borophene-decorated polypyrrole (PPy) nanocomposites (NCs) was developed. The PPy-borophene NCs were prepared using a low-cost sonication method. The sensing performance of the PPy-borophene NCs was investigated by the cyclic voltammetry (CV) technique against various biomolecules such as glucose, maltose, lactose, fructose, and urea. According to the electrochemical results, it was observed that in the glucose concentration range of 1.5 to 24 mM within a voltammetric cycle of 1 min, the PPy-based sensor and PPy-borophene NCs-based sensor exhibited sensitivities of 11.88 ?AmM?1 cm?2 and 213.42 ?AmM?1 cm?2, respectively. The detection limits of the PPy-based and PPy-borophene NCs-based sensors were determined to be 0.5 µM and 0.04 µM, respectively. Furthermore, selectivity measurement results revealed that the proposed non-enzymatic biosensor has remarkably good sensitivity and high selectivity, indicating that common biomolecules (glucose, maltose, lactose, fructose, and urea) could be captured by the sensor. Consequently, it was proven that the proposed biosensor could be a potential device for diabetes diagnosis.
Highly sensitive and selective rGO based Non-Enzymatic electrochemical sensor for propamocarb fungicide pesticide detection
(Elsevier Sci Ltd, 2022) Taşaltın, Nevin; Karakuş, Selcan; Taşaltın, Cihat; Baytemir, Gülsen
In this study, reduced graphene oxide (rGO) was prepared using a green ultrasonic microwave assisted method and investigated rGO based non-enzymatic electrochemical sensor for detecting a synthetic fungicide as a propamocarb (PM) pesticide. The rGO-based sensor exhibited rapid response within 1 min, low detection limit of 0.6 mu M and wide linear range of (1-5) mu M with a high sensitivity of 101.1 mu A mu M- 1 cm-2 for PM. Besides this, the sensor detected the propamocarb pesticide on the real cucumber sample with high sensitivity in the concentration range of (1-5) mu M within a 1-minute cycle. The sensor is highly selective against propamocarb pesticide. The prepared non-enzymatic electrochemical sensor exhibited high sensitivity, high selectivity, reproducibility, and rapid response.
A new perspective towards diagnosis of sleep apnea: Isoprene detection using Pssa-G-Panı based saw sensor
(Afyon Kocatepe Üniversitesi, 2022) Taşaltın, Cihan; Baytemir, Gülsen; Taşaltın, Nevin
Obstrüktif Uyku Apne Sendromu (OSAS) tarafından tetiklenen hücresel metabolik değişiklikler, nefeste OSAS'ın biyobelirteci olarak izopren saptanarak invazif olarak tespit edilir. Uykuya dalındığında izopren seviyesi 3 ppm'nin üzerine çıkmaya başlar. Bu nedenle, normal koşullar altında solunan nefeste izopren seviyelerinin izlenmesi, uyku apnesi gibi uyku bozukluklarını tespit etmek, izlemek ve kontrol etmek için invazif olmayan bir yöntem sağlayabilir. Bu çalışmada, PSSA-g-PANI tabanlı SAW gaz sensörleri hazırlanmış ve izopren gaza karşı test edilmiştir. Sensör ölçümleri, PSSA-g-PANI tabanlı SAW tipi sensörün yüksek hassasiyetle (1-150) ppm izopren gazı algıladığını ve dolayısıyla PSSA-g-PANI tabanlı SAW tipi sensörün uyku apnesinin izlenmesini ve kontrolünü sağlayabileceğini ortaya koymaktadır.
Nickel phthalocyanine-borophene nanocompositebased electrodes for non-enzymatic electrochemical detection of glucose
(J Mater Sci: Mater Electron, 2022) Baytemir, Gülsen; Gürol, İlke; Karakuş, Selcan; Taşaltın, Cihat; Taşaltın, Nevin
As diabetes has become one of the major health problems affecting hundreds of millions of people worldwide, the development of electrochemical sensors for the detection of glucose is crucial. Herein, the fabrication of nickel phthalocyanine (NiPc)-based and NiPc-borophene nanocomposite-based non-enzymatic electrochemical sensors for glucose detection at room temperature was demonstrated. The electrical conductivities of NiPc and NiPc-borophene nanocomposite have been measured as 3 9 10- 13 S cm-1 and 9.5 9 10-9 S cm-1 , respectively. The electrical conductivity of NiPc has been improved with the addition of borophene. Due to the high charge transport advantages of the borophene additive, the sensor sensitivity and detection limit have been improved. In voltammetric cycle of 60 s for the 1.5–24 mM glucose concentration range, NiPc-based sensor has a sensitivity value of 0.08 lAmM-1 cm-2 , while the NiPc-borofen nanocomposite-based sensor has a much higher sensitivity of 10.31 lAmM-1 cm-2 . The limit of detection values of the NiPc and NiPc-borophene nanocomposite-based sensors are 3 lM and 0.15 lM, respectively. The borophene nanosheets with good chemical stability and high carrier mobility have been shown to be a good candidate to form nanocomposite structure with NiPc for glucose detection.
PANI: Ni(Leu)2 based non-enzymatic electrochemical dopamine sensor
(Iop Publishing Ltd, 2023) Yıldız, Dilber Esra; Baytemir, Gülsen; Taşaltın, Nevin; Karakuş, Selcan; Gursu, Gamze; Kose, Dursun Ali
In this study, metal complexes of Leucine (Leu) and Tryptophan (Trip), namely nickel(Leucine)(2) (Ni(Leu)(2)), zinc(Leucine)(2) (Zn(Leu)(2)), cobalt(Leucine)(2) (Co(Leu)(2)), copper(Leucine)(2) (Cu(Leu)(2)), nickel(Tryptophan)(2) (Ni(Trip)(2)), zinc(Tryptophan)(2) (Zn(Trip)(2)), cobalt(Tryptophan)(2) (Co(Trip)(2)), and copper(Tryptophan)(2) (Cu(Trip)(2)), were synthesized. These complexes were then utilized to fabricate nanocomposites (NCs) based on polyaniline (PANI) through a straightforward sonochemical technique. These NCs were then used to fabricate non-enzymatic electrochemical sensors for detecting dopamine (DOP). The results indicate that the PANI:Ni(Leu)(2) NCs based sensor has a high sensitivity of 28.47 mu A mu M-1 cm(-2) and a low limit of detection (LOD) of 9.24 mu M. Also, the sensor was tested against fructose, glucose, lactose, and maltose. The sensitivities of the sensor against fructose, glucose, and lactose were calculated as 2.90 mu Acm(-2) mM(-1), 2.14 mu Acm(-2) mM(-1), 2.81 mu Acm(-2) mM(-1), respectively. Due to the use of Ni(Leu)(2) composition, the DOP detection sensitivity was higher in PANI:Ni(Leu)(2) NCs which can be explained by an enhanced redox mechanism. Furthermore, PANI:Ni(Leu)(2) sensor is selectively detect DOP. The PANI:Ni(Leu)(2) NCs based sensor is a particularly promising candidate for application in biomedical test kits due to its rapid detection.
PEDOT: PSS / ?12 borophene nanocomposites as an inorganic-organic hybrid electrode for high performance supercapacitors
(Elsevier, 2022) Türkmen, Tülin Ateş; Taşaltın, Nevin; Taşaltın, Cihat; Baytemir, Gülsen; Karakuş, Selcan
İki boyutlu inorganik borofen nano tabakaları bazlı nanoformülasyonlar enerji alanında büyük ilgi görüyor Üstün esneklikleri, yüksek kapasitansları nedeniyle süper kapasitörlerin geliştirilmesine yönelik depolama uygulamaları, ve iletkenlik özellikleri. Burada yeni bir poli(3,4-etilendioksitiyofen): polistirenin hazırlanması Basit çözüm yaklaşımı kullanılarak sülfonat (PEDOT: PSS) / ?12 Borofen nanokompozit elektroaktif malzeme oda sıcaklığında kanıtlanmıştır. ?12 faz kristal yapıya sahip borofen hazırlandı (PEDOT: PSS) / ?12 Borofen inorganik-organik hibritte kullanılacak kolay ve düşük maliyetli bir sonikasyon yöntemi ile elektrot üretimi. Elektrokimyasal ölçümler PEDOT'un spesifik kapasitanslarını ortaya çıkardı: PSS elektrotu, PEDOT: PSS / Borofen (ağırlıkça %75/25) elektrot ve PEDOT: PSS / Borofen (ağırlıkça %50/50) elektrot sırasıyla 230 Fg-1, 622 Fg-1, 853 Fg-1 idi. PEDOT'un kapasitans tutma değeri: PSS / Borofen (%50 Borofen) elektrot 1000 döngüden sonra %95 oldu, PEDOT: PSS / Borofen olduğunu ortaya çıkardı elektrotlar iyi stabiliteye sahiptir PEDOT: PSS / Borofen (ağırlıkça %50/50) potansiyel bir elektroaktif nanomateryaldir yüksek performanslı süper kapasitörler için.
PVA:Nano-eggshell microcomposite as an energy storage material for supercapacitors
(J Mater Sci: Mater Electron, 2022) Taşaltın, Nevin; Karakuş, Selcan; Tüzün, Elif; Taşaltın, Cihat; Baytemir, Gülsen
The development and advantages of wearable flexible electronics have become attractive issues with excellent electrochemical performances in energy storage devices. In this study, we highlighted a low cost and green fabrication of biosupercapacitor using poly(vinyl alcohol) (PVA):Nano-eggshell microcomposites. As it is known, interest in the production of green supercapacitors is increasing rapidly. A uniform PVA:Nano-eggshell microcomposite morphology was obtained in the polymer blend-based nanostructure using kappa-carrageenan as the matrix. PVA:Nano-eggshell microcomposites were prepared and coated on a Ni foam. The performance of PVA:Nano-eggshell microcomposites-Ni foam-based supercapacitor was investigated. Kappa-carrageenan was used to increase the specific capacity due to the large number of free charges. The proposed supercapacitor showed a high specific capacitance of 255 F/g in [0, 1] V range at 100 mV/s scan rate. These results demonstrated that the proposed electrode of PVA:Nano-eggshell microcomposites is to be a promising high performance and flexible supercapacitor in energy storage applications.
Ultra-sensitive smartphone assisted-colorimetric and non-enzymatic electrochemical sensor behaviors of zinc doped MnO2 nanocomposite: a comparative study on highly selective sensor design against dopamine, ascorbic acid, gallic acid, and tannic acid
(Springer Heidelberg, 2023) Tan, Ezgi; Baytemir, Gülsen; Taşaltın, Nevin; Karakuş, Selcan
Although evolving technology enables the production of sensors with excellent properties, the development of a fast-response, portable, and low-cost sensor is very important for food detection and also for disease diagnosis. Herein, zinc doped manganese oxide nanocomposites (Zn:MnO2 NCs) were designed as smartphone-integrated colorimetric and non-enzymatic electrochemical sensors with high sensitivity and selectivity. According to the Transmission electron microscopy (TEM) results showed that the Zn:MnO2 NCs had a spherical shape with a uniform particle size of less than 10 nm. As one of the most important results, the colorimetric sensing behavior of the Zn:MnO2 NCs was showed excellent fast and selective sensitivity against dopamine, ascorbic acid, gallic acid, and tannic acid among the various bio-analytes such as sugars, amino acids, hormones, and phenolic compounds. The Zn:MnO2 NCs were successfully used as smartphone supported paper based sensor against dopamine, gallic acid, and tannic acid using RGB analysis and with low limit of detection (LOD) values of 2.89, 3.88, and 7.81 mu M, respectively. Moreover, Zn:MnO2 exhibited excellent a non-enzymatic electrochemical sensor performance against ascorbic acid with a low LOD of 239 nM and high sensitivity of 44.73 mu A/cm(2) mM in a concentration range of 0.52-11.35 mM. These findings emphasize that the designed Zn:MnO2 NCs based sensors has a potential as easily applicable and rapid sensor systems against of ascorbic acid, gallic acid, tannic acid and dopamine for real food and blood samples that as a point-of-care detection systems.

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