Conventional Colorimetric Method Research Articles

Direct and Sensitive Electrochemical Determination of Total Antioxidant Capacity in Foods Using Nanochannel-Based Enrichment of Redox Probes.

Simple and sensitive determination of total antioxidant capacity (TAC) in food samples is highly desirable. In this work, an electrochemical platform was established based on a silica nanochannel film (SNF)-modified electrode, facilitating fast and highly sensitive analysis of TAC in colored food samples. SNF was grown on low-cost and readily available tin indium oxide (ITO) electrode. Fe3+-phenanthroline complex-Fe(III)(phen)3 was applied as the probe, and underwent chemical reduction to form Fe2+-phenanthroline complex-Fe(II)(phen)3 in the presence of antioxidants. Utilizing an oxidative voltage of +1 V, chronoamperometry was employed to measure the current generated by the electrochemical oxidation of Fe(II)(phen)3, allowing for the assessment of antioxidants. As the negatively charged SNF displayed remarkable enrichment towards positively charged Fe(II)(phen)3, the sensitivity of detection can be significantly improved. When Trolox was employed as the standard antioxidant, the electrochemical sensor demonstrated a linear detection range from 0.01 μM to 1 μM and from 1 μM to 1000 μM, with a limit of detection (LOD) of 3.9 nM. The detection performance is better that that of the conventional colorimetric method with a linear de range from 1 μM to 40 μM. Owing to the anti-interfering ability of nanochannels, direct determination of TAC in colored samples including coffee, tea, and edible oils was realized.

Evaluation of Antibiotic Penicillin G Activities Based on Electrochemical Measurement of a Tetrazolium Salt.

This study focused on the electrochemical properties of tetrazolium salts to develop a simple method for evaluating viable bacterial counts, which are indicators of drug susceptibility. Considering that the oxidized form of tetrazolium, which has excellent cell membrane permeability, changes to the insoluble reduced form formazan inside the cell, the number of viable cells was estimated based on the reduction current of the tetrazolium remaining in the bacterial suspension. Dissolved oxygen is an important component of bacterial activity. However, it interferes with the electrochemical response of tetrazolium. We estimated the number of viable bacteria in the suspension based on potential-selective current responses that were not affected by dissolved oxygen. Based on solubility, cell membrane permeability, and characteristic electrochemical properties of the tetrazolium salt 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium, we developed a method for rapidly measuring viable bacteria within one-fifth of the time required by conventional colorimetric methods for drug susceptibility testing.

Dual-modification strategy of Co(II) and g-C3N4 to CuS for efficient colorimetric determination of thioglycolic acid in daily cosmetics

A conventional colorimetric method based on CuS-catalyzed H2O2 is improved by a dual-modification strategy and employed for thioglycolic acid (TGA) determination. The doping of Co(II) can enhance ion exchange efficiency. Meanwhile, the modification of g-C3N4 can increase specific surface area and decrease unspecific aggregation. The constructed g-C3N4/Co-CuS nanocomposite exhibited a favorable catalytic feature. A Michaelis constant (Km) value of 0.02 mM has been achieved, which is 1/160 ofthose of CuS and horseradish peroxidase (HRP). The g-C3N4/Co-CuS displays a rapid color response in 3min and resulted in a stable measurable signal within 10min. In the determination procedure, the sulfhydryl contained in TGA is capable of preventing TMB oxidation via competing the ·OH produced by catalysis and caused a color distinction that is related to the TGA amount. The distinctions of absorbance (λmax = 652nm) of different concentrations of TGA are recorded. Linearity is obtained in the ranges of 2.5 - 20µM and 20 - 160µM, and the LOD is 0.14µM. In the real sample assays of perm agent and Qianhu lake water, the recoveries were 96.70 - 106.84% and 100.21 - 101.90%, respectively. This demonstrates that the proposed dual-modification strategy for CuS contributes to highly efficient and convenient determination of TGA in daily cosmetics and water analysis.

Simultaneous determination of intracellular reduced and oxidized glutathiones by the König reaction.

The König reaction is commonly used for the detection of cyanide and its derivatives, including thiocyanate and selenocyanate. We found that this reaction can be used to quantify glutathione fluorometrically, and applied it to the simultaneous determination of reduced and oxidized glutathiones (GSH and GSSG) using a conventional LC system with isocratic elution. The limits of detection were 6.04 nM and 9.84 nM for GSH and GSSG, respectively, and the limits of quantification were 18.3 nM and 29.8 nM, respectively. We also determined GSH and GSSG levels in PC12 cells exposed to paraquat, an oxidative stressor, and observed a decrease in GSH/GSSG ratio, as expected. Total GSH levels quantified by this method and by the conventional colorimetric method with 5,5'-dithiobis(2-nitrobenzoic acid) were comparable. Our new application of the König reaction offers a reliable and useful method to simultaneously quantify intracellular GSH and GSSG.

Development of an HPV Genotype Detection Platform Based on Aggregation-Induced Emission (AIE) and Flow-Through Hybridization Technologies.

Genetic mutations can cause life-threatening diseases such as cancers and sickle cell anemia. Gene detection is thus of importance for disease-risk prediction or early diagnosis and treatment. Apart from genetic defects, gene detection techniques can also be applied to gene-related diseases with high risk to human health such as human papillomavirus (HPV) infection. HPV infection has been strongly linked to cervical cancer. To achieve a high-throughput HPV gene detection platform, the flow-through hybridization system appears to be one of the commercialized diagnostic techniques for this purpose. The flow-through hybridization technique is based on a vacuum-guided flow of DNA fragments which is continuously directed toward the oligoprobes that are immobilized on the testing membrane. However, the conventional colorimetric method and signal read-out approach suffers a problem of low sensitivity. On the contrary, fluorescence approaches allow more sensitive detection and broad sensing ranges. In this work, a fluorescent dye HCAP, which possesses aggregation-induced emission (AIE) properties and is responsive to alkaline phosphatase, was developed and applied to the flow-through hybridization platform to achieve HPV genome diagnosis of clinical samples. Also, an automatic membrane reader was constructed based on the AIE-based diagnosis platform which can identify the diagnostic result of patient DNA with a total concordance rate of 100% in the clinical trial.

Sequential Injection Amperometric System Coupling with Bioreactor for In-Line Glucose Monitoring in Cell Culture Application

We proposed a specially designed sequential injection (SI) amperometric system coupling with a bioreactor for in-line glucose monitoring in cell culture. The system is composed of three main parts which are the bioreactor, SI system, and electrochemical detection unit. The bioreactor accommodates six individual cell culture units which can be operated separately under different conditions. The SI system enables automatic in-line sampling and in-line sample dilution, with a specially designed mixing unit; therefore, it has the benefits of fast analysis time and less contamination risk. The use of 3D-printed microfluidic components, a mixing channel, and a flow cell helped to reduce operational time and sample volume. A disposable screen-printed electrode (SPE), modified with glucose oxidase (GOD), carbon nanotube, and gold nanoparticle, was used for detection. The developed system provided a linear range up to 3.8 mM glucose in cell culture media. In order to work with cell culture in higher glucose media, the in-line sample dilution can be applied. The developed SI system was demonstrated with mouse fibroblast (L929) cell culture. The results show that glucose concentration obtained from the SI system is comparable with that obtained from the conventional colorimetric method. This work can be further developed and applied for in vitro cell-based experiments in biomedical research.

PMMA/paper hybrid microfluidic chip for simultaneous determination of arginine and valine in human plasma.

Thesimultaneous determination is reported of arginine (Arg) and valine (Val) amino acids in plasma using flower-shaped μPADs and PMMA/paper hybrid microfluidic chip based on AuNPs capped with R-thiazolidine-4-carboxylic acid (THP). In this article, the evaluation procedure is based on the smartphone colorimetric detection mechanism that results from the aggregation of the THP-AuNPs with the addition of amino acids and visual color change from red to blue. Arg and Val were selectively determined with good reproducibility and an acceptable linearity range. The flower-shaped (μPADs) provides many advantages, including low cost, reasonable sensitivity, simple and fast performance, simultaneous detection, disposable use, and high sample throughput compared with conventional colorimetric method using cuvette cells. The ratios between the absorbance wavelength at (A650/A525) and (A685/A525) are linearly proportional to the concentration of Arg and Val. Under the optimum conditions, the calibration range in aqueous solutions is 0.0068-100.0 and 0.0056-75.0µM with a limit of detection of 2.25 and 1.86nM for Arg and Val at pH 7.0, respectively. In the case of μPADs, the calibration curves for Arg and Val showed good linearity in the concentration range 0.01-75.0µM. The detection limits for the analytes were 3.51nM and 3.44nM for Arg and Val, respectively. In addition, a PMMA/paper hybrid microfluidic chip was successfully employed to determine Arg and Val in plasma samples with a relative error below 5%.

Portable smartphone-based colorimetric system for simultaneous on-site microfluidic paper-based determination and mapping of phosphate, nitrite and silicate in coastal waters.

Early and on-site detection of environmental contaminations and physicochemical parameters of seawater is increasingly preferred to guarantee hazard minimization in many settings. In this paper, we describe a combination of microfluidic paper-based sensors (µPADs) and an Android-based smartphone application (App) for simultaneous on-site quantification of phosphate (PO4-P), silicate (SiO3-Si) and nitrite (NO2-N) in coastal seawater samples. The developed App can on-site capture, process, and quantify the µPAD colorimetric outputs. This App uses an image processing algorithm for quantifying color intensity and relating the RGB components to the analyte concentrations. The GPS-tagged data can be stored on the smartphone or sent via social networks. The significant factors affecting the detection of the analytes were optimized using Box-Behnken design. Under optimized parameters, the proposed method presented the linear ranges between 5 and 100µg L-1 for phosphate (R2 = 0.9909), 5 to 100µg L-1 (R2 = 0.9819) for nitrite and 10 to 600µg L-1 (R2 = 0.9933) for silicate. The LODs of the method for detection of phosphate, nitrite and silicate were 1.52µg L-1, 0.61µg L-1 and 3.74µg L-1, respectively. The device was successfully used to simultaneous analyze and map the PO4-P, SiO3-Si and NO2-N of Bushehr coastal seawater samples (Iran). The results were confirmed by the lab-based conventional colorimetric methods using spectrophotometer.

A new method for detecting Na+ , K+ -ATPase activity by ICP-MS: Quantitative analysis on the inhibitory effect of rhein on Na+ , K+ -ATPase activity by ICP-MS in HCT116 cells.

Rhein is an active component from Chinese herbal medicine. It can cause diarrhea by inhibiting Na+ , K+ -ATPase activity on intestinal epithelial cells, thus decreasing the re-absorption of Na+ from intestinal tract to blood. However, when this Na+ , K+ -ATPase inhibition was quantitated by a colorimetric method that measures ATPase-catalyzed release of inorganic phosphorus, the data obtained were inconsistent and showed great variation. We developed a novel method using inductively coupled plasma mass spectrometry (ICP-MS) to quantitate the amount of intracellular Rb+ . This method largely mimics the 86 RbCl tracer flux assay, but it uses non-radioactive RbCl as a flux substrate. The results demonstrated that this method has better precision and accuracy than the conventional colorimetric method. More importantly, this method is free from radioactive substances, which is expected to make it safer and more convenient than the radioactive 86 RbCl tracer flux method. In conclusion, the ICP-MS method for Na+ , K+ -ATPase activity determination is novel and accurate. It can also provide a reference for studying the transport of other metal ions across membranes under biological conditions.

Visualized Discriminant Analysis and Recognition of Multiple Metal Ions with a Single Cellulose-Based Fluorescent Probe

Visualized discriminant analysis and recognition can facilitate embracing the advanced and complicated sensing and detection technologies. Herein, the first visual analysis method based on RGB–CMYK color systems is established for the recognition of multiple metal ions. Such a visual method is accomplished by only a single fluorescent probe CA-TPY, a cellulose derivative containing terpyridine. The color responses (color changes or fluorescence variations) between CA-TPY and metal ions are creatively illustrated with a graphical representation. Seven metal ions (Ag+, Fe2+, Co2+, Fe3+, Zn2+, Cd2+, and Al3+) can be easily recognized and distinguished without depending on the sensibility of the naked eye to color change. It is a very humanistic technique for people with color blindness and superior to conventional colorimetric visual methods. The approach reported herein could provide new insights into visualized analysis in chemical sensing far beyond the paper-based applications, including rapid test strips, rewritable paper, water-jet printing, and security patterns.

Association of the CYP1A1 rs4646903 polymorphism with susceptibility and severity of coronary artery disease.

Given the significant physical, mental, and economic problems of coronary artery disease (CAD), it is important for communities to help reduce these costs. The Cytochrome P450 Family 1 Subfamily A Member 1) CYP1A1 (enzyme is known to cause coronary artery disease through various mechanisms. Therefore, it is important to investigate the polymorphisms that affect the activity of this enzyme. After collecting samples from 191 patients with angiographically verified CAD and 191 healthy individuals, genotyping for CYP1A1 rs4646903 polymorphism was carried out. Lipid profile was assessed by conventional colorimetric method. The results showed that the frequency of heterozygous and homozygous mutant genotypes of rs4646903 polymorphism was 36.6% and 5.2% in patients and 20.9% and 2.1% in controls, respectively. The heterozygous genotype (OR=2.24; 95% CI=1.30-3.84, P=0.003), homozygous mutant genotype (OR=3.97; 95% CI=1.05-14.98, P=0.042) and mutant C allele (OR=2.15; 95% CI=1.46-3.15, P<0.001) was significantly associated with CAD risk. Further analysis identified CYP1A1 rs4646903 polymorphism as a significant risk factor for early onset (P= 0.005) but not late onset (P=0.066) CAD. However, the frequency of heterozygous and homozygous mutant genotype of rs4646903 polymorphism did not differ significantly among the CAD patients with various number of stenotic vessel (P>0.05). In conclusion, the rs4646903 polymorphism contributed to the susceptibleness of people to CAD.

Turbine Blade Three-Wavelength Radiation Temperature Measurement Method Based on Reflection Error Correction

The turbine blade is a key component in an aeroengine. Currently, measuring the turbine blade radiation temperature always requires obtaining the emissivity of the target surface in advance. However, changes in the emissivity and the reflected ambient radiation cause large errors in measurement results. In this paper, a three-wavelength radiation temperature measurement method was developed, without known emissivity, for reflection correction. Firstly, a three-dimensional dynamic reflection model of the turbine blade was established to describe the ambient radiation of the target blade based on the real surface of the engine turbine blade. Secondly, based on the reflection correction model, a three-wavelength radiation temperature measurement algorithm, independent of surface emissivity, was proposed to improve the measurement accuracy of the turbine blade radiation temperature in the engine. Finally, an experimental platform was built to verify the temperature measurement method. Compared with three conventional colorimetric methods, this method achieved an improved performance on blade temperature measurement, demonstrating a decline in the maximum error from 6.09% to 2.13% and in the average error from 2.82% to 1.20%. The proposed method would benefit the accuracy in the high-temperature measurement of turbine blades.

Electrochemical Detection of Serum Antibodies Against Mycobacterium avium Subspecies paratuberculosis.

Mycobacterium avium subsp. paratuberculosis (MAP) causes a chronic inflammatory intestinal disease, called Johne's disease (JD) in many ruminants. In the dairy industry, JD is responsible for significant economic losses due to decreased milk production and premature culling of infected animals. Test-and-cull strategy in conjunction with risk management is currently recommended for JD control in dairy herds. However, current diagnostic tests are labor-intensive, time-consuming, and/or too difficult to operate on site. In this study, we developed a new method for the detection of anti-M. paratuberculosis antibodies from sera of M. paratuberculosis-infected animals. M. paratuberculosis antigen-coated magnetic beads were sequentially reacted with bovine serum followed by a horseradish peroxidase (HRP)-labeled secondary antibody. The reaction of HRP with its substrate was then quantitatively measured electrochemically using a redox-active probe, ferrocyanide. After optimization of electrochemical conditions and concentration of the redox-active probe, we showed that the new electrochemical detection method could distinguish samples of M. paratuberculosis-infected cattle from those of uninfected cattle with greater separation between the two groups of samples when compared with a conventional colorimetric testing method. Since electrochemical detection can be conducted with an inexpensive, battery-operated portable device, this new method may form a basis for the development of an on-site diagnostic system for JD.

Low-Cost Quantitative Photothermal Genetic Detection of Pathogens on a Paper Hybrid Device Using a Thermometer.

Tuberculosis (TB), one of the deadliest infectious diseases, is caused by Mycobacterium tuberculosis (MTB) and remains a public health problem nowadays. Conventional MTB DNA detection methods require sophisticated infrastructure and well-trained personnel, which leads to increasing complexity and high cost for diagnostics and limits their wide accessibility in low-resource settings. To address these issues, we have developed a low-cost photothermal biosensing method for the quantitative genetic detection of pathogens such as MTB DNA on a paper hybrid device using a thermometer. First, DNA capture probes were simply immobilized on paper through a one-step surface modification process. After DNA sandwich hybridization, oligonucleotide-functionalized gold nanoparticles (AuNPs) were introduced on paper and then catalyzed the oxidation reaction of 3,3',5,5'-tetramethylbenzidine (TMB). The produced oxidized TMB, acting as a strong photothermal agent, was used for the photothermal biosensing of MTB DNA under 808 nm laser irradiation. Under optimal conditions, the on-chip quantitative detection of the target DNA was readily achieved using an inexpensive thermometer as a signal recorder. This method does not require any expensive analytical instrumentation but can achieve higher sensitivity and there are no color interference issues, compared to conventional colorimetric methods. The method was further validated by detecting genomic DNA with high specificity. To the best of our knowledge, this is the first photothermal biosensing strategy for quantitative nucleic acid analysis on microfluidics using a thermometer, which brings fresh inspirations on the development of simple, low-cost, and miniaturized photothermal diagnostic platforms for quantitative detection of a variety of diseases at the point of care.

Nitrosonaphthol reaction-assisted SERS assay for selective determination of 5-hydroxyindole-3-acetic acid in human urine

Urinary 5-hydroxyindole-3-acetic acid (5-HIAA) is a marker for diagnosis of patients with carcinoid tumors. In clinical practice, a simple colorimetric assay has widely been utilized for urinary 5-HIAA via its reaction with 1-nitroso-2-naphthol (NNa) in nitrous acid medium. However, this colorimetric assay has been criticized for lack of specificity. Herein, we proposed a novel SERS-based method for selective detection of urinary 5-HIAA by the use of a modified nitrosonaphthol reaction, in which hydrochloric acid is substituted for nitric acid to control the reaction conditions. This slight modification is crucial to be able to detect the cationic products in the acidic reaction mixture, because the chloride-aggregated Ag colloids not only create enormous hot spots for SERS enhancement, but also improve the chemical stability of nanostructured Ag substrates in acidic environment. Under optimized conditions, the present method can detect 5-HIAA within 12 min at concentrations as low as 1.2 ng/mL, which is 1000 times lower than that of conventional colorimetric method. And more importantly, the present method exhibits specific response toward 5-HIAA against other metabolites with similar structures in the urine. The relative standard deviation (RSD) of the present method is less than 5%, suggesting the acceptable reproducibility. The recoveries ranging from 89.6% to 106.3% were obtained for spiked human urine samples with RSD of 3.7–4.9%. Furthermore, several healthy person’s urine samples were also analyzed using the present method, and experimental results are in compliance with the levels recorded in a healthy population. On the basis of these results we can conclude that the present SERS-based method can provide a valuable alternative to conventional colorimetric assay for clinical diagnosis, evaluating prognosis, and monitoring of treatment in carcinoid tumors.

Patterned Superhydrophobic SERS Substrates for Sample Pre-Concentration and Demonstration of Its Utility through Monitoring of Inhibitory Effects of Paraoxon and Carbaryl on AChE.

We describe a patterned surface-enhanced Raman spectroscopy (SERS) substrate with the ability to pre-concentrate target molecules. A surface-adsorbed nanosphere monolayer can serve two different functions. First, it can be made into a SERS platform when covered by silver. Alternatively, it can be fashioned into a superhydrophobic surface when coated with a hydrophobic molecular species such as decyltrimethoxy silane (DCTMS). Thus, if silver is patterned onto a latter type of substrate, a SERS spot surrounded by a superhydrophobic surface can be prepared. When an aqueous sample is placed on it and allowed to dry, target molecules in the sample become pre-concentrated. We demonstrate the utility of the patterned SERS substrate by evaluating the effects of inhibitors to acetylcholinesterase (AChE). AChE is a popular target for drugs and pesticides because it plays a critical role in nerve signal transduction. We monitored the enzymatic activity of AChE through the SERS spectrum of thiocholine (TC), the end product from acetylthiocholine (ATC). Inhibitory effects of paraoxon and carbaryl on AChE were evaluated from the TC peak intensity. We show that the patterned SERS substrate can reduce both the necessary volumes and concentrations of the enzyme and substrate by a few orders of magnitude in comparison to a non-patterned SERS substrate and the conventional colorimetric method.

Determination of Saccharides in Environments Using a Sulfuric Acid-Fluorescence Approach.

Accurate, rapid, and reliable quantification of saccharides is essential for understanding their behaviors and roles in environmental processes. However, the conventional colorimetric method for saccharide quantification fails to discriminate between fructose and glucose, resulting in the misestimation of total saccharides. To solve this problem, a fluorescence approach, that is, parallel factor framework-linear regression analysis, was developed in this work to quantify the specific fluorescence signatures of the fluorescent products generated from the reaction between saccharides and sulfuric acid. The fluorescent derivatives of saccharides were recognized and the simultaneous quantification of glucose and fructose was achieved with a detection limit of 2.9 μg/mL and 1.3 μg/mL, respectively. Furthermore, 200 μg/mL of the treated sorbitol and gluconic acid only, respectively, equaled to 6 μg/mL and 3 μg/mL of the treated glucose, indicating their negligible interference for the saccharide quantification using this method. In addition, the feasibility and robustness of this method in environmental applications were validated with the recovery tests using spiked real water samples. This fluorescence-based approach offers a new tool to monitor saccharides in complex environments.

AC impedance measurement for the enzyme kinetics of urea–urease system: a model for impedimetric biosensor

The measurement of time evolution of electrochemical impedance enables enzymatic kinetic studies in real-time, and obviates the need of using additional reagents as in many popular spectroscopic methods. This can eventually lead to the development of enzyme biosensors. We have used the urea–urease system as a model for this study. The usage of a free enzyme (without any immobilization steps) in this work makes the technique very simple and unique for electrochemical measurement on urease. The impedance vs. time measurement of urease exhibits Michaelis–Menten (MM) behaviour with the MM constant ( $$K_{\mathrm {{m}}}$$ ) of 0.8 mM and maximum velocity ( $$V_{\mathrm {{max}}}$$ ) of $$5000\hbox { ohms min}^{{{-1}}}$$ . This $$K_{\mathrm {{m}}}$$ value closely matched the one, which is obtained from the conventional colorimetric method (values). The enzyme kinetics was performed in a standard three-electrode system and reproduced in a fabricated mini electrochemical cell in an Eppendorf tube, which could pave the way for the development of impedimetric biosensors for a variety of enzyme systems, especially the ones for which spectrometric techniques cannot be readily applied.

Rapid and sensitive electrochemical detection of anticancer effects of curcumin on human glioblastoma cells

Curcumin, a hydrophobic polyphenol derived from the Curcuma longa plant, is known to affect various cellular activities such as cell cycle regulation, oncogene expression, apoptosis, and mutagenesis, and is thus considered a promising candidate for an anticancer drug. In this study, we report the development of a platform that is effective to evaluate the anticancer effects of curcumin on one of the most aggressive tumors, glioblastoma. To generate platforms that satisfy both rapid and sensitive detection of curcumin effects, the surface of transparent conductive electrodes was first modified with two different types of electrocatalytic materials, gold and silver nanoparticles, with different densities. Among the four different substrates fabricated, a high-density gold nanostructure film (HDGN) in combination with peptide modification was found to be the best in terms of measuring the electrochemical signals of human glioblastoma cells (U87MG). The electrical signals of U87MG cells (Epc = -0.05 V vs. Ag/AgCl), obtained from cyclic voltammetry, showed excellent linearity (R2 = 0.99) within the range of 20,000–60,000 cells, and were thus demonstrated to be suitable for assessment of curcumin anticancer effects on U87MG cells. A clear curcumin toxicity on human glioblastoma was found with concentrations higher than 30 μM, which was consistent with the results obtained from cell counting kit-8 (CCK-8) assays. Remarkably, unlike the conventional colorimetric methods, the HDGN/peptide-modified platform was completely free from a possible signal interference from curcumin (absorbance: 425 nm). In addition, it enabled rapid (detection time < 3 min) and precise (limit of quantification: 9379 cells/chip) assessments of the potential toxicity of curcumin for cancer cells. Hence, we conclude that the developed platform is highly promising for use as a high-throughput screening tool for the discovery of new types of less toxic plant-derived natural anticancer drugs.

Analysis of the Influence of Substrate Formulations on the Bioactive Chemical Profile of Lingzhi or Reishi Medicinal Mushroom, Ganoderma lucidum (Agaricomycetes) by Conventional and Chemometrics Methods.

Ganoderma lucidum, a mushroom with medicinal properties, can grow on diverse lignocellulosic substrates. Substrate enrichment with additives has been used as a strategy to increase mushroom productivity. In this study, we evaluated the impact of substrate formulation on the bioactive chemical profile of the basidiome. The bioactive chemical profile of basidiomes cultivated on rice agro-residues (RA) or sunflower seed hulls (SSH) enriched with olive oil and/or copper was evaluated using conventional colorimetric methods and FT-MIR spectrometry coupled with chemometrics. The contents of total triterpenoids, ganoderic acids, high-molecular-weight carbohydrates, and phenolic compounds were sensitive to substrate formulation and harvest time. Moreover, cluster analysis and principal component analysis of the mid-IR spectra were able to discriminate between basidiomes cultivated on either RA or SSH substrates, and for SSH substrates between enriched and nonenriched formulas. These results indicate that the bioactive composition of G. lucidum can be influenced by the formulation of the cultivation substrate.