Sensitive Chemiluminescence Method Research Articles

Determination of ampicillin sodium using the cupric oxide nanoparticles–luminol–H2O2 chemiluminescence reaction

A simple and sensitive chemiluminescence (CL) method has been developed for the determination of ampicillin sodium at submicromolar levels. The method is based on the inhibitory effect of ampicillin sodium on the cupric oxide nanoparticles (CuO NPs)-luminol-H2 O2 CL reaction. Experimental parameters affecting CL inhibition including concentrations of CuO NPs, luminol, H2 O2 and NaOH were optimized. Under optimum conditions, the calibration plot was linear in the analyte concentration range 4.0 × 10(-7) -4.0 × 10(-6) mol/L. The limit of detection was 2.6 × 10(-7) mol/L and the relative standard deviation (RSD) for six replicate determinations of 1 × 10(-6) mol/L ampicillin sodium was 4.71%. Also, X-ray diffraction (XRD) and transmission electron microscopy (TEM) analysis were employed to characterize the CuO NPs. The utility of the proposed method was demonstrated by determining ampicillin sodium in pharmaceutical preparation.

A novel chemiluminescence assay of mitoxantrone based on diperiodatocuprate(III) oxidation

A novel and strong chemiluminescence (CL) of luminol with diperiodatocuprate (K5[Cu(HIO6)2]) was observed in alkaline medium. After the addition of mitoxantrone (MTX) into this system, the CL intensity could be greatly inhibited by MTX. Based on the phenomenon, a sensitive CL method was established for analysis of MTX combining with flow injection technology. Under optimum experimental conditions, the CL intensity was linearly related to the logarithm concentration of MTX from 5.0×10−9–1.0×10−7g/ml with the detection limit of 1.1×10−9g/ml (S/N=3). The relative standard deviation was 1.2% for 5.0×10−8g/ml of MTX. The proposed method was successfully applied for determination of MTX in pharmaceutical preparations and biological fluids. The possible CL reaction mechanism was also discussed briefly.

Sensitive determination of 2‐methoxyestradiol in pharmaceutical preparations and serum samples using flow injection chemiluminescence

A rapid and sensitive flow injection chemiluminescence (FI-CL) method is described for the determination of 2-methoxyestradiol (2ME) based on enhancement of the CL intensity from a potassium ferricyanide-calcein system in sodium hydroxide medium. The optimum conditions for the CL emission were investigated. Under optimized conditions, a linear calibration graph was obtained over the range 1.0 × 10(-8) to 1.0 × 10(-6) mol/L (r = 0.998) 2ME with a detection limit (3σ) of 5.4 × 10(-9) mol/L. The relative standard deviation (RSD) for 5.0 × 10(-7) mol/L 2ME was 1.7%. As a preliminary application, the proposed method was successfully applied to the determination of 2ME in injection solutions and serum samples. The possible CL mechanism was also proposed.

A validated silver‐nanoparticle‐enhanced chemiluminescence method for the determination of citalopram in pharmaceutical preparations and human plasma

A simple and sensitive chemiluminescence (CL) method was developed for the determination of citalopram in pharmaceutical preparations and human plasma. The method is based on the enhancement of the weak CL signal of the luminol-H2 O2 system. It was found that the CL signal arising from the reaction between alkaline luminol and H2 O2 was greatly increased by the addition of silver nanoparticles in the presence of citalopram. Prepared silver nanoparticles (AgNPs) were characterized by UV-visible spectroscopy and transmission electron microscopy (TEM). Various experimental parameters affecting CL intensity were studied and optimized for the determination of citalopram. Under optimized experimental conditions, CL intensity was found to be proportional to the concentration of citalopram in the range 40-2500 ng/mL, with a correlation coefficient of 0.9997. The limit of detection (LOD) and limit of quantification (LOQ) of the devised method were 3.78 and 12.62 ng/mL, respectively. Furthermore, the developed method was found to have excellent reproducibility with a relative standard deviation (RSD) of 3.65% (n = 7). Potential interference by common excipients was also studied. The method was validated statistically using recovery studies and was successfully applied to the determination of citalopram in the pure form, in pharmaceutical preparations and in spiked human plasma samples. Percentage recoveries were found to range from 97.71 to 101.99% for the pure form, from 97.84 to 102.78% for pharmaceutical preparations and from 95.65 to 100.35% for spiked human plasma.

Flow‐injection chemiluminescence determination of gentamicin: optimization by central composite design

A simple and sensitive flow-injection chemiluminescence (CL) method has been developed for the determination of gentamicin sulfate. The method is based on the inhibitory effect of gentamicin on the CL emission accompanying oxidation of luminol by H2 O2 in an alkaline medium in the presence of Cu(II) as a catalyst. Inhibition was caused by the formation of a strong complex between analyte and the catalyst. Experimental variables, including the concentrations of luminol (µmol/L), H2 O2 (mol/L), Cu(II) (mol/L) and NaOH (mol/L), were optimized using a central composite design. Under optimum conditions, the plot of CL intensity versus gentamicin concentration was found to have two linear ranges. One range was at low concentrations from 1.0 to 10.0 mg/L and the other was from 10.0 to 30.0 mg/L. Precision was calculated by analyzing samples containing 5.0 mg/L gentamicin (n = 11) and the relative standard deviation (RSD) was 1.7%. Also, a high injection throughput of 120 samples/h was achieved. This method was successfully applied to the determination of gentamicin sulfate in pharmaceutical formulations and water samples.

Sensitive Detection of DNA Methyltransferase Using Hairpin Probe-Based Primer Generation Rolling Circle Amplification-Induced Chemiluminescence

DNA methyltransferases (MTases) catalyze the transfer of a methyl group from S-adenosylmethionine (SAM) to the 5-positon of cytosine in CpG islands, eventually inducing the DNA methylation in both prokaryotes and eukaryotes. Despite the development of various methods for the MTase assay, most of them are laborious and costly with poor sensitivity. Herein, we develop a highly sensitive chemiluminescence method for the MTase assay using hairpin probe-based primer generation rolling circle amplification (PG-RCA). In the presence of DNA adenine methylation (Dam) MTase, the methylation-responsive sequence of hairpin probe is methylated and cleaved by the methylation-sensitive restriction endonuclease Dpn I. The cleaved hairpin probe then functions as a signal primer to initiate PG-RCA reaction by hybridizing with the circular DNA template, producing a large number of horseradish peroxidase-mimicking DNAzyme chains, which can catalyze the oxidation of luminal by H2O2 in the presence of hemin to yield distinct chemiluminescence signal. While in the absence of Dam MTase, neither methylation/cleavage nor PG-RCA reaction can be initiated and no chemiluminescence signal is observed. The proposed method exhibits a wide dynamic range from 0.025 to 400 U/mL and an extremely low detection limit of 1.29 × 10(-4) U/mL, which is superior to most conventional approaches for the MTase assay. This method can be used for the screening of antimicrobial drugs and has a great potential to be further applied in early clinical diagnosis.

Flow‐injection chemiluminescence determination of olanzapine using N‐chlorosuccinimide–calcein reaction sensitized by zinc (II)

A novel, rapid and sensitive chemiluminescence (CL) method combined with flow-injection (FI) has been established for the estimation of olanzapine. This method is based on the CL signal generated between N-chlorosuccinimide and olanzapine in an alkaline medium in the presence of calcein and Zn(II). Under optimum conditions, the CL signal was proportional to the olanzapine concentration ranging from 1.0 × 10(-10) to 3.0 × 10(-7) g/mL. The detection limit is 8.9 × 10(-11) g/mL olanzapine (3σ) and the relative standard deviation for 3.0 × 10(-9) g/mL of olanzapine is 1.9% (n = 11). The current CL method was applied to determine olanzapine in pharmaceutical formulations and biological fluids with satisfactory results. The possible CL reaction mechanism is discussed briefly.

Chemiluminescence determination of trimetazidine via inducing the aggregation of gold nanoparticles

A simple, rapid and sensitive chemiluminescence (CL) method combined with flow injection analysis was developed for the determination of trimetazidine. Trimetazidine was found to significantly increase the CL signal arising from N-bromosuccinimide-luminol reaction in the presence of gold nanoparticles. The enhanced CL intensity was proportional to trimetazidine concentration in the range of 0.01–5.0μg/mL, with a limit of detection (3sb) of 6.7ng/mL. The relative standard deviation was 2.8% for 11 repetitive measurements of 0.1μg/mL trimetazidine solution. The practicality of the method was evaluated by determining trimetazidine in pharmaceutical formulations and in spiked human serum samples. Moreover, the possible CL reaction mechanism was also discussed.

Chemiluminescence microfluidic system on a chip to determine vitamin B1 using platinum nanoparticles triggered luminol–AgNO3 reaction

A novel and sensitive chemiluminescence (CL) method on a microchip has been presented for the determination of vitamin B1 (VB1). The microchip was fabricated by soft lithographic procedure using polydimethyl siloxane (PDMS) having four inlets and one outlet with a 200μm wide, 250μm height, 6mm diameter and 100mm long microchannel. The method is based on the enhanced CL intensity of luminol by its oxidation with AgNO3 in the presence of platinum nanoparticles (PtNPs). It was found that the oxidation of luminol with AgNO3 by PtNPs produced strong CL signal at about 425nm which meant that the luminophore was still 3-aminopthalate. The CL intensity of the luminol–AgNO3–PtNPs system was further increased with the addition of VB1. Under optimum conditions, the CL intensity was increased by increasing the concentration of VB1 in the range of 1.0×10−7 to 4.0×10−5molL−1 with a correlation coefficient of 0.9992. The limit of detection was found to be 4.8×10−9molL−1 with the relative standard deviation of 1.06%. The method was successfully applied to determine VB1 in vitamin B1 tablets and vitamin B complex tablets. The interaction mechanism of the CL system has been proposed by UV–vis spectra and CL emission spectra.

PP129: Sirolimus levels in blood vs. saliva in chronically treated patients – A rational basis for topical use

Purpose Sirolimus, currently used as an immunosuppressant, is a potent mammalian target of rapamycin blocker with antiproliferative activity. Its potential for the management of oral pathologies and cancer and has been suggested. Topical application in the oral cavity can enhance availability and efficacy of the drug. The objective of this study was to establish an analytical method for determining sirolimus levels in human saliva in those using sirolimus chronically as well as calculation of the blood vs. saliva ratio. Materials and methods Chemiluminescent microparticle immunoassay technology was used to determine blood and saliva levels of sirolimus in kidney transplant patients. All patients signed informed consent forms and an examination of the oral cavity was performed, clinical findings and oral symptoms, if any, were recorded along with the medical status of the patient. Blood and saliva samples were collected at the same time and analyzed. The study was approved by the institutional review board. Results An analytical method for determining sirolimus levels in human saliva was established. Four patients were enrolled in the study. In all patients medication blood levels were stable. None of the patients had pathological lesions in their oral cavities. A substantial variability was observed among samples. No linear correlation was found. The saliva levels were on average four times lower than blood levels. Conclusions The sensitive Chemiluminescent microparticle immunoassay method determined sirolimus levels both in saliva and blood in treated patients. Sirolimus saliva levels are significantly lower than blood levels.These results emphasize the need for delivery methods with better oral topical biological availability and reinforce the rationale for using sirolimus topically for the treatment of responsive oral pathologies.

Flow injection chemiluminescence determination of naphazoline hydrochloride in pharmaceuticals

A simple and sensitive flow injection chemiluminescence (FI-CL) method was developed for the determination of naphazoline hydrochloride (NPZ). The method is based on the enhancing effect of NPZ on the weak CL signal from the reaction of KIO4 with H2 O2 . Experimental parameters that affected the CL signal, including the pH of the KIO4 solution, concentrations of KIO4 , H2 O2 and disodium-EDTA and flow rate were optimized. Under the optimum conditions, the increment of CL intensity was linearly proportional to the concentration of NPZ in the range 5.0 × 10(-6) to 70 × 10(-6) mol/L. The detection limit was 1.0 × 10(-6) mol/L and the relative standard deviation for 50 × 10(-6) mol/L NPZ solution was 2.8% (n = 11). In addition, a high throughput of 120 samples/h was achieved. The utility of this method was demonstrated by determining NPZ in pharmaceuticals.

Determination of ferulic acid by flow injection chemiluminescence analysis based on enhancement of theN-bromobutanimide-eosin-CrCl3system in alkaline solution

A simple and sensitive flow injection chemiluminescence method has been developed for the determination of ferulic acid (FA) based on the significant enhancement effect of FA on the CL signal of the N-bromobutanimide (NBS)-eosin-CrCl3 system in alkaline solution. Under optimum conditions, the enhanced CL intensity is linearly related to the concentration of FA in its pharmaceutical preparations and human plasma samples. The corresponding linear regression equations were established over the 4.0 × 10(-10)-1.0 × 10(-7) g/mL for FA tablets and 2.0 × 10(-10)-1.0 × 10(-7) g/mL for plasma samples. The limit of detection for FA tablets and limit of quantification for plasma samples were 2.8 × 10(-10) g/mL (3 σ) and 3.04 × 10(-10) g/mL (10 σ), respectively. A complete analysis could be performed within 40 s, including washing and sampling, giving a throughput of ≈90/h. The proposed method was successfully applied to the determination of FA in pharmaceutical preparations and human plasma samples with satisfactory results. The recoveries of pharmaceutical preparations and human plasma samples at three different concentrations were 97.8-102.6% and 96.7-104.0%, respectively. Furthermore, the possible mechanism of CL reactions was also discussed briefly.

Determination of Salicylic Acid in Human Serum and Urine Samples by High-Performance Liquid Chromatography with Post-column Ru(bipy)32+-Ce(SO4)2 Chemiluminescence Detection

A sensitive, novel and rapid chemiluminescence (CL) method combined with high-performance liquid chromatography (HPLC) separation for the determination of salicylic acid (SA) is described in this work. The method was based on the fact that SA could significantly enhance the CL of the reaction of cerium sulfate and the tris(2,2-bipyridyl) ruthenium(II) CL system in the presence of acid. Under the optimal conditions, the CL intensity was linear over concentrations of SA in the range of 0.02-10 × 10(-6) g/mL, with a detection limit of 8 × 10(-9) g/mL (S/N = 3). Also, the relative standard detection was 2.2% for 1.0 × 10(-7) g/mL (n = 11). The proposed method has been successfully applied to the analysis of SA in human serum samples and urine samples with satisfactory results.

Sensitive chemiluminescence determination of phentolamine mesylate and phenoxybenzamine hydrochloride based on K3Fe(CN)6–H2O2–fluorescein

A new, rapid and sensitive flow-injection chemiluminescence (FI-CL) method was developed and validated for the determination of two alpha (α)-adrenoreceptor blockers: phentolamine mesylate (PM) and phenoxybenzamine hydrochloride (PH). The method was based on the finding that K3Fe(CN)6 and H2O2 could oxidize fluorescein in an alkaline medium to produce a CL signal, and the joining of PM or PH could enhance the CL intensity significantly. A series of chemical and instrumental parameters affecting the CL response was investigated. Under the optimum conditions, the relative CL intensity was proportional to the concentration of sample solutions in the range 3×10−8 to 1×10−6g/mL for PM and 5×10−8 to 5×10−6g/mL for PH. The detection limits were 0.53ng/mL for PM (r2=0.9947) and 2.60ng/mL for PH (r2=0.9791). For 11 repeated measurements of 1.0×10−6g/mL sample solutions, the relative standard deviations (RSDs) were <3.6%. The proposed method has been successfully applied to the analyses of PM and PH in injections and PH in tablets. A brief discussion on the possible CL reaction mechanism is presented.

Flow‐injection chemiluminescence determination of diazepam by oxidation with N‐bromosuccinimide

A rapid and sensitive flow-injection chemiluminescence (FI-CL) method is described for the determination of diazepam based on its reaction with N-bromosuccinimide (NBS) in alkaline medium in the presence of dichlorofluorescein (DCF) as an effective energy-transfer agent. Under optimum conditions, the proposed method allowed the measurement of diazepam over the range of 2.0 × 10(-6) to 2.0 × 10(-4) mol/L with a detection limit of 5.0 × 10(-7) mol/L. The relative standard deviation for 11 parallel measurements of 2.0 × 10(-5) mol/L diazepam was 2.1%. The method was applied satisfactorily for the determination of diazepam in pharmaceutical preparations, and the results agree well with those obtained by spectrophotometry. The use of the proposed system for the determination of diazepam in urine and plasma samples was also tested. The possible mechanism of the chemiluminescence reaction is discussed briefly.

Hydroxylamine amplified gold nanoparticle-based aptameric system for the highly selective and sensitive detection of platelet-derived growth factor

This study developed a sensitive and selective aptamer-based chemiluminescent (CL) method for the determination of platelet-derived growth factor (PDGF)-BB using hydroxylamine enlarged gold nanoparticles (Au NPs). Rabbit anti-human PDGF-BB polyclonal antibody was covalently coupled on the 96-well plate that offers reactive N-oxysuccinimide ester (referred to as NOS group) surface. In the presence of target protein, the biotinylated aptamer was captured on the 96-well plate forming an antibody/PDGF-BB/biotinylated aptamer sandwiched complex, which was followed by the assembly of streptavidin coated Au NPs (streptavidin–gold). Au NPs assembled on the surface of 96-well plate reacted with HAuCl4 and NH2OH, which enabled the catalytic deposition of gold metal onto the Au NPs surfaces. A huge number of Au3+ ions were released from the hydroxylamine enlarged Au NPs after oxidative gold metal dissolution, which was determined by a simple and sensitive luminol CL reaction. The results showed that the detection limit of the assay is 60pM of PDGF-BB (corresponding to 6fmol in a 100μL volume), which compares favorably with those of other PDGF-BB detection techniques. In addition, this aptameric CL biosensor demonstrated extraordinary specificity. And PDGF-BB has been determined in diluted serum indicating the applicability of this assay.

Flow injection chemiluminescence determination of isoxicam based on diperiodatoargentate(III)-fluorescein system in a micellar medium

A novel and highly sensitive flow injection chemiluminescence (FI-CL) method has been developed for the assay of isoxicam. The method is based on the luminescence of the diperiodatoargentate(III)-fluorescein-isoxicam system, where fluorescein is used as an energy-transfer reagent in alkaline medium. The emission intensity is greatly enhanced by the presence of cetyltrimethylammonium bromide (CTAB). Optimum conditions and possible mechanisms have been investigated. The relative CL intensity is linear with the isoxicam concentration in the range of 3.0×10−10–1.0×10−6g/ml with a detection limit of 7.0×10−11g/ml (3σ). The relative standard deviation (RSD) is 1.7% at 1.0×10−8g/ml of isoxicam (n=11). The present CL procedure was successfully applied to the determination of isoxicam in pharmaceutical formulations and biological fluids.

A sensitive chemiluminescence method for the determination of cysteine based on silver nanoclusters

We have developed a sensitive chemiluminescent (CL) assay for cysteine. It is based on the use of water-soluble and fluorescent silver nanoclusters (Ag NCs) which are found to be able to strongly enhance the weak CL signal resulting from the redox reaction between Ce(IV) ion and sulfite ion. This enhancement is inhibited by cysteine under appropriate conditions. Taking advantage of this specific CL inhibition, a novel CL method for the sensitive and selective detection of cysteine was developed. This effect is interpreted in terms of an electronic energy transfer from excited state intermediate sulfur dioxide (originating from the CL reaction between Ce(IV) and sulfite ions) to the Ag-NCs. The latter become electronically excited and thus can act as a new source of emission. The method was applied to the determination of cysteine in the range from 5.0 nM to 1.0 μM, with a detection limit at 2.5 nM (S/N = 3).

A sensitive inhibition chemiluminescence method for the determination of 6-mercaptopurine in tablet and biological fluid using the reaction of luminol–Ag(III) complex in alkaline medium

A sensitive inhibition chemiluminescence (CL) method for the determination of 6-mercaptopurine (6-MP) is developed. The mechanism of the CL reaction between Ag(III) complex {[Ag(HIO6)2]5−} and luminol in alkaline solution was proposed, along with the inhibition mechanism of 6-MP on the CL emission. The inhibition degree of CL emission was proportional to the logarithm of 6-MP concentration. The effects of the reaction conditions on CL emission and inhibition were examined. Under the optimized conditions, the detection limit (s/n=3) was 3.7×10−10gml−1. The recoveries of 6-MP were in the range of 97.7–105% with the RSD of 2.1–3.4% (n=5) for tablet samples, 103–106% with the RSDs of 1.1–2.1% for spiked serum sample, and 97.2–101% with the RSD of 2.0–4.5% for spiked urine sample. The accuracy of this method for the tablet analysis was examined by comparing with the pharmacopoeia method. The proposed method was used for the determination of 6-MP at clinically relevant concentrations in real urine and serum samples with satisfactory results.

Luminol–K3Fe(CN)6 chemiluminescence system for the determination of glipizide

A rapid and sensitive flow-injection chemiluminescence (CL) method for the determination of glipizide was developed on the basis of finding that glipizide can enhance the CL intensity of the luminol–K3Fe(CN)6 system. In optimum condition, the increased CL intensity was directly proportional to the concentration of glipizide in the range from 4.0×10−8g/mL to 1.0×10−6g/mL and the detection limit was 1.0×10−8g/mL glipizide. The relative standard deviation (RSD) of the developed method was 2.1% with 11 repeated measurements of 1.0×10−7g/mL glipizide. The developed method has been successfully applied to the analysis of glipizide in its pharmaceutical preparations.