Surface Plasmon Resonance Nanosensor Research Articles

Development of Optical-Based Molecularly Imprinted Nanosensors for Adenosine Detection.

Adenosine nucleoside is an important molecule in human physiology. The levels of adenosine nucleoside in urine and plasma are directly or indirectly related to diseases such as neurodegenerative diseases and cancer. In the present study, adenosine-imprinted and non-imprinted poly(2-hydroxyethyl methacrylate-methacrylic acid) (poly(HEMA-MAA)) surface plasmon resonance (SPR) nanosensors were prepared for the determination of adenosine nucleoside. First, MAA/adenosine pre-polymerization complexes were prepared at different molar ratios using adenosine as a template molecule and methacrylic acid (MAA) as a monomer, and SPR nanosensor surfaces were optimized by determining the highest imprinting factor of the chip surfaces. The surfaces of adenosine-imprinted and non-imprinted SPR nanosensors were characterized by using atomic force microscopy, ellipsometry, and contact angle measurements. Kinetic analyses were made with different concentrations in the range of 0.5-400.0 nM for the detection range with a pH 7.4 phosphate buffer solution. The limit of detection in adenosine aqueous solutions, artificial plasma, and artificial urine was determined to be 0.018, 0.015, and 0.013 nM, respectively. In the selectivity analysis of the developed nanosensors, the selectivity of adenosine SPR nanosensors in solutions at different concentrations was determined by using guanosine and cytidine nucleosides. The relative selectivity coefficients of adenosine-imprinted SPR nanosensors for adenosine/cytidine and adenosine/guanosine are 3.836 and 3.427, respectively. Since adenosine-imprinted SPR nanosensors are intended to be used in medical analysis and research, adenosine analysis has also been studied in artificial urine and artificial plasma samples.

Patulin Imprinted Nanoparticles Decorated Surface Plasmon Resonance Chips for Patulin Detection

In this study, the patulin imprinted and the non-imprinted nanoparticles are synthesized by the two-phase mini emulsion polymerization method and characterized by zeta-size analysis, Fourier transform infrared spectroscopy, and scanning electron microscopy. Afterwards, the patulin imprinted and the non-imprinted nanoparticles are attached on the surface of surface plasmon resonance (SPR) chips. The patulin imprinted and the non-imprinted SPR nanosensors are characterized by using atomic force microscope, ellipsometer, and contact angle measurements. Kinetic studies for patulin detection are carried out in the concentration range of 0.5 nmolar–750 nmolar. The limit of detection and the limit of quantification values are obtained as 0.011 nmolar and 0.036 nmolar, respectively. In all kinetic analysis, the response time is 13 min for equilibration, adsorption, and desorption cycles. The selectivity studies of the patulin imprinted and the non-imprinted SPR nanosensors are determined in the presence of ochratoxin A and aflatoxin B1. In order to demonstrate the applicability, validation studies of the patulin imprinted SPR nanosensor are performed by liquid chromatography-tandem mass spectrometry (LC-MS).

Preparation of surface plasmon resonance-based nanosensor for curcumin detection.

In this study, the curcumin imprinted and the non-imprinted poly(2-hydroxyethyl methacrylate-N-methacryloyl-L-tryptophan) (poly(HEMA-MATrp)) nanoparticle based surface plasmon resonance (SPR) nanosensors were prepared for the detection of curcumin and characterized by zeta-size analysis, Fourier transform infrared spectroscopy, and scanning electron microscopy. After, the curcumin imprinted and the non-imprinted nanoparticles are attached on the surface of SPR chips. The curcumin imprinted and the non-imprinted SPR nanosensors are characterized by using atomic force microscope, ellipsometer, and contact angle measurements. Kinetic studies were carried out with curcumin aqueous solution at a concentration range of 0.01-150 mg/L using the curcumin imprinted and the non-imprinted SPR nanosensors. In all kinetic analysis, the response time is 14 min for equilibration, adsorption, and desorption cycles. The limit of detection and limit of quantification for the curcumin imprinted SPR nanosensors was 0.0012 mg/L and 0.0040 mg/L, respectively. The validity of the curcumin imprinted SPR nanosensors in real samples was carried out using liquid chromatography-tandem mass spectrometry (LC-MS).

SPR nanosensor based on molecularly imprinted polymer film with gold nanoparticles for sensitive detection of aflatoxin B1

Aflatoxins which are highly toxic, immunosuppressive and carcinogenic secondary metabolites produced naturally by Aspergillus flavus fungal species have a harm effect on human and animal health. Label free and rapid sensing of aflatoxin B1 (AFB1) has drawn the increased interest of highly sensitive and selective research. A highly sensitive and selective plasmonic sensing method was developed for the detection of AFB1 based on enhance-surface plasmon resonance nanosensor. Firstly, AFB1 and N-methacryloyl-l-phenylalanine were pre-complexed as a template molecule and functional monomer. Molecularly imprinted polymers with gold nanoparticles were coated onto surface plasmon resonance (SPR) gold chip surface. The AFB1 imprinted nanosensor shown a wide linear range, between 0.0001 ng mL−1 and 10.0 ng mL−1, and the limit of detection is 1.04 pg mL−1. Compared to the non-imprinted nanosensor, the imprinting factor was found to be 5.91. Also, detection studies of AFB1 were performed using various food samples. Finally, SPR nanosensors were performed selectivity, reusability and storage stability analysis.

Surface Plasmon Resonance Nanosensors for Detecting Amoxicillin in Milk Samples with Amoxicillin Imprinted Poly(hydroxyethyl methacrylate‐N‐methacryloyl‐(L)‐ glutamic acid)

AbstractIn this study, SPR based nanosensors were prepared for the detection of amoxicillin (AMOX) in milk samples with using molecular imprinting technique. This study developed to determine the amoxicillin (AMOX) from the commercial and local milk samples. For determination of amoxicillin, polymeric film and nanoparticles consisting of poly(hydroxyethyl methacrylate‐N‐methacryloyl‐(L)‐ glutamic acid) were synthesized onto the surface of the SPR chip by ultra violet polymerization. The characterization of the polymeric film and nanoparticles were determined by zeta sizer, ellipsometry, contact angle and atomic force microscopy measurements. The range of linearity was measured as 0.1‐200 ng/mL for amoxicillin (AMOX) imprinted polymeric film and nanoparticles based SPR nanosensors. The limit of detection for AMOX imprinted polymeric film and nanoparticles based SPR nanosensors were found as 0.0012 ng/mL and 0.0009 ng/mL, respectively. To show the selectivity of surface plasmon resonance nanosensors competitive adsorption of amoxicillin (AMOX), ampicillin (AMP), cephalexin (CEP) and cholesterol (KOL) were investigated. According to the results, AMOX imprinted SPR nanosensors have exhibited low‐detection limit, high sensitivity and selectivity for detection of antibiotic in milk samples.

Selective detection of Escherichia coli caused UTIs with surface imprinted plasmonic nanoscale sensor.

The aim of the present study was developing a surface plasmon resonance (SPR) nanosensor to detect Escherichia coli (E. coli) for the diagnosis of urinary tract infections by using surface imprinted Au nanoparticles (AuNPs) as a recognition element. In order to realize imprinting, Cu(II) ions were used to provide interaction between E. coli cell wall and amine functionalized AuNPs forming cavities on the surface of nanosensor. E. coli surface imprinted AuNPs nanosensor was characterized by using ellipsometry, contact angle measurement, scanning electron microscopy (SEM) and atomic force microscopy (AFM). The real time detection of E. coli was evaluated by using E. coli suspensions in the concentration range of 1 × 103-0.5 × 101 CFU/mL. Combination of the signal enhancing properties of AuNPs and surface imprinting technique provided ultrasensitive detection with a comparatively low limit of detection value (1 CFU/mL) to the SPR nanosensor system. Selectivity experiments were performed by using Staphylococcus aureus, Klebsiella pneumoniae and Pseudomonas aeruginosa. The highest response was recorded for E. coli, as expected. Additionally, the recognition of E. coli even in a complex medium such as artificial urine sample was achieved by the developed nanosensing system. Also, this chip can be used repeatedly without seen signal reducing for four-time consecutive. In the view of these results, it was emphasized that this novel sensing system has a potency for the selective, very sensitive, rapid and real time detection of causative agent in order to diagnose E. coli caused infections.

Design and preparation of imprinted surface plasmon resonance (SPR) nanosensor for detection of Zn(II) ions

A novel Zn(II) ions imprinted poly (2-hydroxyethyl Methacrylate-N-methacryloyl-(L)-histidine methyl ester) poly(HEMAH) surface plasmon resonance (SPR) nanosensor were designed for detection of Zn(II) ions in aqueous solution and artificial plasma providing a low cost, rapid and reliable results compared to other techniques such as atomic absorption spectroscopy, inductively coupled plasma-mass spectrometer, X-ray fluorescence with synchrotron radiation. Zn(II) ions imprinted nanofilm on the SPR chip surface was synthesized by bulk polymerization. Characterization of Zn(II) ions imprinted nanosensor was performed by contact angle measurement, atomic force microscopy (AFM), ellipsometry and Fourier transform infrared spectroscopy-attenuated total reflection (FTIR-ATR). Designed nanosensor was applied for selective detection of Zn(II) ions in aqueous solution within the range of 0.5–1.0 µg/mL. The limit of detection (LOD) and limit of quantification (LOQ) were calculated as 0.19 and 0.64 ng/mL, respectively. Association kinetics analysis, Scatchard, Langmuir, Freundlich, Langmuir–Freundlich, Tempkin and Dubinin-Radushkevich isotherms were analyzed to the experimental data in order to identify the adsorption behavior. The selectivity of the SPR nanosensor was examined by using competitive metal ions such as Cd(II), Cu(II), Pb(II), and Fe(II). To evaluate the imprinting effect of Zn(II) ions imprinted (MIP) and non-imprinted (NIP) nanosensor was also prepared as the control. Repeatability of the response signal was tested by four times adsorption–desorption–regeneration cycle.

Molecularly imprinted based surface plasmon resonance nanosensors for microalbumin detection

Human serum albumin (HSA) is a major blood plasma protein also found in urine where its existence may be a marker of some types of liver or kidney dysfunction. Herein, we fabricated a novel surface plasmon resonance (SPR) nanosensor for selective, sensitive, and label-free microalbumin detection both in aqueous and urine sample solutions. First, HSA-imprinted nanoparticles were synthesized, which consist of ethylene glycol dimethacrylate and N-methacryloyl-L-leucine methyl ester as a cross-linker and functional monomer. The nanoparticles were characterized by zeta-size and scanning electron microscope analyses and were dropped onto the SPR chip surface to make HSA sensitive nanosensor. Characterization studies of HSA-imprinted SPR chip were carried out by atomic force microscopy, Fourier-transform infrared spectroscopy, contact angle, and ellipsometer. The limit of detection and limit of quantification values of HSA-imprinted SPR nanosensor were calculated as 0.7 pM and 1.9 pM for the concentration range of 0.15–500 nM. Selectivity studies of HSA-imprinted SPR nanosensor were achieved with hemoglobin and transferrin proteins which were chosen as competitor molecules. HSA-imprinted SPR nanosensor was displayed highly selective and sensitive to HSA.

Enhanced surface plasmon resonance (SPR) signals based on immobilization of core-shell nanoparticles incorporated boron nitride nanosheets: Development of molecularly imprinted SPR nanosensor for anticancer drug, etoposide

An effective SPR nanosensor based on core-shell nanoparticles (Ag@AuNPs) incorporated hexagonal boron nitride (HBN) nanosheets and molecularly imprinted polymer (MIP) was presented for etoposide (ETO) detection. Scanning electron microscope (SEM), transmission electron microscope (TEM), x-ray diffraction (XRD) method, cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), fourier transform infrared (FTIR) spectroscopy and atomic force microscopy (AFM) methods were utilized for all characterizations of nanomaterials and polymer surfaces. ETO imprinted SPR nanosensor based on Ag@AuNPs-HBN nanocomposite was developed in the presence of poly(2-hydroxyethyl methacrylate-methacryloylamidoglutamic acid) [p(HEMA-MAGA)]. The results of the study have revealed that 0.001–1.00 ng mL−1 (1.70 × 10–12–1.70 × 10−9 M) and 0.00025 ng mL−1 (4.25 × 10–13 M) were found as the linearity range and the detection limit (LOD). Furthermore, the prepared SPR nanosensor was examined in terms of stability, repeatability and selectivity. Finally, the imprinted SPR nanosensor was applied to the urine samples having high recovery.

Detection of ciprofloxacin through surface plasmon resonance nanosensor with specific recognition sites

The novel nanosensor based on Surface Plasmon Resonance (SPR) was developed for sensitive and selective detection of ciprofloxacin via molecularly imprinted nanoparticles (MIP/NPs). NPs were synthesized through miniemulsion polymerization technique with methacrylic acid as a functional monomer. FTIR, SEM, zetasizer and contact angle measurements were used for the characterization of MIP/NPs. After modification the SPR chip surface, the nanosensor was used for detection of ciprofloxacin in aqueous solution. According to selected concentration range, the correlation coefficient and limit of detections were obtained as 0.993 (R2) and 3.21 and 7.1 ppb in ultrapure water and SWW, respectively. Association kinetic analysis, Scatchard, Freundlich, Langmuir and Freundlich-Langmuir isotherms were also performed on the data to investigate adsorption behaviour of ciprofloxacin on the surface of nanosensor. Tetracycline and enrofloxacin were used as competitor agents to examine the selectivity of nanosensor. Performance of the SPR nanosensor was also investigated by using synthetic wastewater (SWW) for detection of CPX. The reusability of nanosensor was investigated and good repeatability was obtained with 5.81% RSD. As a result, selective, simple and low-cost method to detect ciprofloxacin in aqueous solution was developed by combining MIP/NPs and SPR.

Large-area gold nanohole arrays fabricated by one-step method for surface plasmon resonance biochemical sensing.

Surface plasmon resonance (SPR) nanosensors based on metallic nanohole arrays have been widely reported to detect binding interactions in biological specimens. A simple and effective method for constructing nanoscale arrays is essential for the development of SPR nanosensors. In this work, we report a one-step method to fabricate nanohole arrays by thermal nanoimprinting in the matrix of IPS (Intermediate Polymer Stamp). No additional etching process or supporting substrate is required. The preparation process is simple, time-saving and compatible for roll-to-roll process, potentially allowing mass production. Moreover, the nanohole arrays were integrated into detection platform as SPR sensors to investigate different types of biological binding interactions. The results demonstrate that our one-step method can be used to efficiently fabricate large-area and uniform nanohole arrays for biochemical sensing.

Presentation of a multilayer nanosensor for gas detection by palladium-membrane with emphasis on hydrogen gas

Hydrogen gas sensors, based on palladium membranes, have considerable applications in areas such as industry, aerospace, and green energy monitoring. In this paper, we propose a surface plasmon resonance nanosensor, in which the main metal sensor is taken to be gold with a thin nanolayer of palladium membrane. The reason we chose palladium is its exceptional property of having high permittivity to hydrogen penetration. In this paper, formation of palladium hydride (PdH$_{x}$, where x = H / Pd) is achieved and simulation is provided using Materials Studio software. Based on an intermediate assumption, a semiconductor gold composite layer is used instead of gold, because the composite layer gives higher efficiency. In the final structure, twelve alternating layers of gold and silicon are used (silicon and gold with thicknesses of 0.53 and 13.6 nm, respectively). The proposed structure is simulated under carbon monoxide exposure to analyze its cross-sensitivity to other gases. Finally, the sensor shows higher sensitivity and narrower linewidth under hydrogen exposure compared to carbon monoxide exposure.

Plastic antibody based surface plasmon resonance nanosensors for selective atrazine detection

This study reports a surface plasmon resonance (SPR) based affinity sensor system with the use of molecular imprinted nanoparticles (plastic antibodies) to enhance the pesticide detection. Molecular imprinting based affinity sensor is prepared by the attachment of atrazine (chosen as model pesticide) imprinted nanoparticles onto the gold surface of SPR chip. Recognition element of the affinity sensor is polymerizable form of aspartic acid. The imprinted nanoparticles were characterized via FTIR and zeta-sizer measurements. SPR sensors are characterized with atomic force microscopy (AFM), scanning electron microscopy (SEM), Fourier transform infrared spectrophotometry (FTIR) and contact angle measurements. The imprinted nanoparticles showed more sensitivity to atrazine than the non-imprinted ones. Different concentrations of atrazine solutions are applied to SPR system to determine the adsorption kinetics. Langmuir adsorption model is found as the most suitable model for this affinity nanosensor system. In order to show the selectivity of the atrazine-imprinted nanoparticles, competitive adsorption of atrazine, simazine and amitrole is investigated. The results showed that the imprinted nanosensor has high selectivity and sensitivity for atrazine.

Utilization of chloramphenicol imprinted nanoparticles in surface plasmon resonance nanosensors

Utilization of chloramphenicol imprinted nanoparticles in surface plasmon resonance nanosensors

Fabrication of surface plasmon resonance nanosensor for the selective determination of erythromycin via molecular imprinted nanoparticles

The main objective of this study was to develop a novel surface plasmon resonance (SPR) nanosensor method based on a more rapid and selective determination of erythromycin (ERY) in the aqueous solution. This study is a combination of three techniques, which are miniemulsion polymerization, molecular imprinting and surface plasmon resonance techniques. In the first part, nanoparticles prepared with methacryl groups of functional monomer at surface acted as reactive sites for erythromycin as a template molecule. The molecularly imprinted nanoparticles were characterized by FTIR, SEM and zetasizer. After immobilization of nanoparticles on gold surface of SPR chip, nanosensor was characterized with contact angle measurements. This nanosensor was then used for selective determination of erythromycin. The linearity range and detection limit were obtained as 0.99 (r2) and 0.29ppm, respectively. Association kinetic analysis, Scatchard, Langmuir, Freundlich and Freundlich–Langmuir isotherms were applied data. The selectivity of the SPR nanosensor was determined by using competitor agents (kanamycin sulfate, neomycin sulfate, spiramycin). The non-imprinted nanosensor was also used to evaluate the selectivity of ERY imprinted nanosensor. Finally, the nanosensor was tested for repeatability and it gave satisfactory response. These results demonstrate a method which is of low cost, rapid and provide reliable results in order to be used in detection of erythromycin from aqueous solution.

A sensitive molecular imprinted surface plasmon resonance nanosensor for selective determination of trace triclosan in wastewater

Triclosan (TCS) has been widely used as an antibacterial and antifungal agent in household cleaning and personal care products. The widespread use of TCS in the cleaning products poses a potential risk to the ecological system and human health due to its release into sediments, wastewater and ground water resources causing chronicle toxicity to aquatic organisms. However, no simple method is available for its detection and quantitative determination in aqueous solution. A novel molecular imprinted surface plasmon resonance (SPR) chemical sensor was developed for sensitive and selective detection of triclosan (TCS) in wastewater, using allylmercaptane modified gold SPR chip and imprinted poly(2-hydroxyethyl methacrylate–methacryloylamidoglutamic acid) [p(HEMAGA)] nanofilm. The unmodified and imprinted surfaces of the SPR chip were characterized by Fourier transform infrared (FTIR) spectroscopy, atomic force microscopy (AFM) and contact angle measurements. The developed sensor was validated according to the ICH guideline (International Conference on Harmonisation). The linearity range and detection limit of TCS were obtained as 0.05–1.0ng/mL and 0.017ng/mL, respectively. The developed molecular imprinted nanosensor was successfully applied to wastewater samples for the determination of TCS and exhibited excellent performance.

Fabrication of SPR Nanosensor Using Gold Nanoparticles and Self-Assembled Monolayer Technique for Detection of Cu2+ in an Aqueous Solution

In this work, we investigated the fabrication of surface plasmon resonance (SPR) nanosensor using gold nanoparticles (AuNPs) chemisorbed onto self assembled monolayer of 10-(3-amino phenoxy) decane-1-thiol on gold substrate. The fabrication process of SPR nanosensor was characterized using different techniques such as infrared reflection-absorption spectra (IRRAS), xX-ray photoelectron spectroscopy (XPS), and atomic force microscope (AFM). The fabricated SPR nanosensor was used for detection of Cu2+ in an aqueous solution using surface plasmon resonance refractometer. The results confirm the fabrication of new SPR nanosensor. The fabricated SPR nanosensor showed a good activity toward the detection of Cu2+. The detection of Cu2+ in an aqueous solution using the fabricated SPR nansensor was enhanced in the presence of gold nanoparticles.

Determination of amikacin in human plasma by molecular imprinted SPR nanosensor

The molecular imprinting technique depends on the molecular recognition. It is polymerization method occuring around the target molecule. Thus this technique creates specific cavities in the cross-linked polymeric matrices. Amikacin (AMIK) is an important aminoglycoside (AG) antibiotic used to treat different types of bacterial infections. In this study, we prepared surface plasmon resonance (SPR) sensor for the determination of AMIK in human plasma. After the modification of gold surface of SPR chip was performed by allyl mercaptane, AMIK-imprinted poly(2-hydroxyethyl methacrylate-methacryloylamidoaspartic acid) [p(HEMA–MAAsp)] film was generated on the allyl mercaptane modified gold surface. The non-modified and imprinted surfaces were characterized by Fourier transform infrared (FTIR) spectroscopy, atomic force microscopy (AFM) and contact angle measurements. The developed method was validated according to the ICH guideline. The linearity range and the detection limit were obtained as 0.01–0.15μg/mL and 0.0025μg/mL (4.3×10−9mol/L), respectively. The developed AMIK-imprinted nanosensor was successfully applied to the human plasma samples for the determination of AMIK.

Chemisorption assembly of Au nanorods on mercaptosilanized glass substrate for label-free nanoplasmon biochip

The fabrication of a localized surface plasmon resonance nanosensor in a chip based format that utilizes Au nanorods (GNRs) as the optical transducer were systematically studied. (3-mercaptopropyl)trimethoxysilane (MPTMS) modified glass substrate offers GNR deposition with maximal sensitivity to local refractive index changes, which subsequently results in better optical recognition of receptor–analyte binding. Kinetics governing the mass transport and chemisorption of nanorods from bulk to solid surface can be dynamically controlled in a predictable fashion. We demonstrate that slight aggregation induced by a low ionic strength (5mM NaCl) can facilitate the nanorod assembly to result in a dense, well-distributed surface monolayer. In high ionic media (e.g. 40–80mM), anions present electrostatically bind with the positively charged cetyltrimethylammonium bromide (CTAB) surrounding nanorod surfaces, thereby leading to instability with heavy aggregation in solution. However, once chemically bound on silanized substrates, the nanorods exhibit excellent stability in physiological buffer where high amount of ionic species are present. The fundamental study is followed by demonstration of a practical application of the fabricated biochip in label-free detection based on GNR wavelength shift of the longitudinal palsmon maxima as the optical signature of human IgG model detection.

Combining molecular imprinted nanoparticles with surface plasmon resonance nanosensor for chloramphenicol detection in honey

AbstractThe focus of this article is to develop a surface plasmon resonance (SPR) nanosensor to determine chloramphenicol (CAP) using the molecularly imprinted nanoparticles. The CAP imprinted nanoparticles were prepared by miniemulsion polymerization method. Then, the nanoparticles were attached onto the SPR nanosensor surface via temperature‐controlled evaporation. Surface characterization studies were performed with atomic force microscopy and contact angle measurements. Kinetic studies were performed with CAP solutions in the concentration range of 0.155–6.192 nM. Florphenicol (FLP) and thiamphenicol (TAP) having similar chemical structures to the template (i.e., CAP) were chosen as competitors to determine selectivity of the nanoparticles. Selectivity constants were observed as 8.86 for CAP/TAP and 8.36 for CAP/FLP. The detection limit was calculated as 40 ng/kg honey sample. In the light of these results, it was emphasized that the SPR nanosensor is able to recognize CAP selectively and has a potential for real‐time CAP detection in honey sample. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013