A Critical Review on Clinical Application of Separation Techniques for Selective Recognition of Uracil and 5-Fluorouracil.

The most important objectives that are frequently found in bio-analytical chemistry involve applying tools to relevant medical/biological problems and refining these applications. Developing a reliable sample preparation step, for the medical and biological fields is another primary objective in analytical chemistry, in order to extract and isolate the analytes of interest from complex biological matrices. Since, main inborn errors of metabolism (IEM) diagnosable through uracil analysis and the therapeutic monitoring of toxic 5-fluoruracil (an important anti-cancerous drug) in dihydropyrimidine dehydrogenase deficient patients, require an ultra-sensitive, reproducible, selective, and accurate analytical techniques for their measurements. Therefore, keeping in view, the diagnostic value of uracil and 5-fluoruracil measurements, this article refines several analytical techniques involved in selective recognition and quantification of uracil and 5-fluoruracil from biological and pharmaceutical samples. The prospective study revealed that implementation of molecularly imprinted polymer as a solid-phase material for sample preparation and preconcentration of uracil and 5-fluoruracil had proven to be effective as it could obviates problems related to tedious separation techniques, owing to protein binding and drastic interferences, from the complex matrices in real samples such as blood plasma, serum samples.

Rapid immobilization of viable Bacillus pseudomycoides in polyvinyl alcohol/glutaraldehyde hydrogel for biological treatment of municipal wastewater.

A new approach for easy synthesis of Bacillus pseudomycoides immobilized polyvinyl alcohol (PVA)/glutaraldehyde (GA) hydrogel for application in a wastewater treatment system is reported. Optimization studies revealed that GA/PVA mass ratio of 0.03 and acidic pH of 2 were required for hydrogel synthesis and eventually for bacterial cell immobilization. The synthesized crosslinked matrix possessed a pore size suitable for microbial cell entrapment while maintaining cell accessibility to external environment for bioremediation. Possible crosslinking and bacterial cell immobilization in the hydrogel were evidenced by FTIR, XRD, and SEM studies, respectively. Further, the extent of crosslinking of GA with PVA was investigated and confirmed by transmittance and permeability experiments. The viability and proliferation of hydrogel embedded cells (after 25 days) was confirmed by confocal fluorescence microscopy which also indicated that acidic pH of polymer solution did not affect the immobilized live cells. B. pseudomycoides immobilized hydrogel were demonstrated to be effective for treatment of municipal wastewater and reduced biochemical oxygen demand (BOD), chemical oxygen demand (COD), and protein content below the recommended levels. Overall, the results from this bench-scale work show that employing bacteria-embedded PVA/GA hydrogel for the treatment of municipal wastewater yield promising results which should be further explored in pilot/field-scale studies.

Zwitterionic molecularly imprinted polymer-based solid-phase micro-extraction coupled with molecularly imprinted polymer sensor for ultra-trace sensing of L-histidine.

The proposed L-histidine sensing system composed of a molecularly imprinted solid-phase microextraction component combined with a molecularly imprinted polymer sensor was used to determine critical levels of test analyte in a complex matrix of highly diluted human blood serum without any non-specific sorption and false-positive contributions. The molecularly imprinted polymer was a zwitterionic polymer brush derived from the disodium salt of EDTA and chloranil, grafted to solid-phase microextraction material. The hyphenated approach was able to detect L-histidine quantitatively with a limit of detection as low as 0.0435 ng/mL (RSD = 0.2%, S/N = 3).

Ultratrace analysis of uracil and 5-fluorouracil by molecularly imprinted polymer brushes grafted to silylated solid-phase microextraction fiber in combination with complementary molecularly imprinted polymer-based sensor.

Main inborn errors of metabolism diagnosable through uracil (Ura) analysis and the therapeutic monitoring of toxic 5-fluorouracil (5FU) in dihydro pyrimidine dehydrogenase (DPD) deficient patients require a sensitive, reproducible, selective and accurate method. In this work, an artificial receptor in the format of molecularly imprinted polymer (MIP) brush 'grafted to' the surface of sol-gel immobilized on cost-effective homemade solid-phase microextraction (SPME) fibers, individually imprinted with either of Ura and 5FU, was used in combination with a voltammetric sensor duly modified with the same MIP. This combination provided up to 10- and 8.4-fold preconcentrations of Ura and 5FU, respectively, which was more than sufficient for achieving stringent detection limits in the primitive diagnosis of uracil disorders and fluoropyrimidine toxicity in DPD-deficient patients. The proposed method permits the assessment of Ura and 5FU plasma concentrations with detection limits pf 0.0245 and 0.0484 ng mL(-1) (RSD = 1.0-2.5%, S/N = 3), respectively, without any problems of non-specific false-positives and cross-reactivities in complicated matrices of biological samples.

Electrocatalytic Imprinted Polymer of N-Doped Hollow Carbon Nanosphere-Palladium Nanocomposite for Ultratrace Detection of Anticancer Drug 6-Mercaptopurine.

In this work, a nanohybrid-based imprinted polymer consisting of N-doped hollow carbon nanospheres and palladium is reported for the electroanalysis of ultratrace level of anticancer drug, 6-mercaptopurine, used in the treatment of leukemia. For this, N-doped carbon nanospheres decorated with palladium were first developed, and subsequently, a molecular imprinted polymer layer was grown onto their surfaces. The so-produced silica-embedded nanocomposite was made hollow by etching silica moieties with hydrofluoric acid. Finally, the whole system was doped on an ionic-liquid-modified pencil graphite electrode. The underlying synergistic effect of hollow carbon nanosphere-supported palladium nanoparticles inculcated electrocatalytic action. Notably, all rebinding sites in solid core-shells were confined within the shell, which hampers the effective diffusion of template. However, in this work, an effective diffusion of template across the hollow structure of inner and outer surfaces was observed. Consequently, this rendered approximately 2-fold heterogeneous rate constant as compared to the solid core-shell-based sensor. Differential pulse voltammetric transduction was used for ultratrace detection of 6-mercaptopurine through anodic stripping method. The hollow imprinted sensor revealed a linear dependence of current with concentration range 0.80-70.748 ng mL-1. The limits of detection 0.11-0.22 ng mL-1 were realized in water, human blood plasma, urine, and pharmaceuticals. Thus, the proposed sensor demonstrated an attractive sensitivity reproducibility, as well as endurance requisite for the treatment of leukemia patients.

Functionalized nitrogen doped graphene quantum dots and bimetallic Au/Ag core-shell decorated imprinted polymer for electrochemical sensing of anticancerous hydroxyurea.

A novel molecularly imprinted polymer-capped acrylated nitrogen doped graphene quantum dots and bimetallic Au/Ag core-shell was synthesized to serve as a sensing nano-hybrid film for the detection of an anticancerous drug, hydroxyurea. This exploited the use of a functionalized nitrogen doped graphene quantum dots iniferter. This initiated the polymerization, following "surface grafting-from" approach, over the surface of a screen-printed carbon electrode to obtain requisite stability and selectivity of the measurement. Herein, nitrogen doped graphene quantum dots were prepared utilizing the degree of dehydration/carbonization of citric acid (carbon skeleton) and urea (nitrogen dopant) as source materials. This provided an efficient sensor platform anchoring bimetallic Au/Ag core-shell on its surface. The nano-assembly of acrylated nitrogen doped graphene quantum dots and bimetallic Au/Ag core-shell@imprinted polymer actually amplified the electrode kinetics by improving the diffusion coefficient (~20-fold) and electron-transfer kinetics (~5-fold), in comparison to the simple bimetallic Au/Ag core-shell decorated imprinted sensor. Under optimized conditions of differential pulse anodic stripping voltammetric transduction, a linear relationship between the current and the concentration was obtained in the range of 0.62-102.33 ng mL-1 for hydroxyurea. The detection limit was observed to be 0.07 ng mL-1 in blood plasma, without having any matrix effect, cross-reactivity, and false-positives. The proposed sensor assures its clinical applicability for the treatment of cancer.

Electrochemical simultaneous analysis of dopamine and epinephrine using double imprinted One MoNomer acryloylated graphene oxide-carbon black composite polymer.

A novel One MoNomer dual imprinted graphene oxide/carbon black composite polymer was developed applying 'surface-grafting from' approach on the screen printed carbon electrode for the electrochemical sensing of dopamine and epinephrine. Acryloylated-graphene oxide/carbon black was synthesized for the first time. This served both as a crosslinker and monomer leading to the fast electron transfer from the redox centre to the electrode. The oxidation peak potentials of both the targets were found separated by 200 mV which enabled their simultaneous analysis in real world samples, without any cross reactivity, interferences, and false-positives. The detection limits realized by the proposed sensor, under optimized analytical conditions, were found to be as low as 0.028, 0.028,0.061 and 0.029 ng mL-1 for dopamine and 0.017, 0.018, 0.019 and 0.020 ng mL-1 for epinephrine (S/N = 3) in aqueous, blood serum, urine and pharmaceutical samples. Such sensor could be considered suitable for the primitive diagnosis of several chronic diseases, manifested at ultra-trace level.

Enantioselective analysis of D- and l- Serine on a layer-by-layer imprinted electrochemical sensor.

The present work describes a new, simple, and easy method of generating acrylamide functionalised reduced graphene oxide-fullerene layer-by-layer assembled dual imprinted polymers to quantify D- and L-Serine at ultra trace level in aqueous and real samples. Herein, the pencil graphite electrode was initially spin coated with D-Serine imprinted acrylamide functionalized reduced graphene oxide. After 10 min thermal treatment (50 °C), this electrode was again modified with L-Serine imprinted acrylamide functionalized fullerene molecules. This bilayer assembly was finally made thermally stable by 60 °C exposure for 3 h. The proposed sensor showed better electronic properties with an improved synergism. We have compared this modified electrode with other modified pencil graphite electrodes like single layered acrylamide functionalised reduced graphene oxide or fullerene, single layered acrylamide functionalised reduced graphene oxide-fullerene composite and double layered acrylamide functionalised reduced graphene oxide or fullerene molecules, which yielded very inferior sensitivity due to possible agglomeration and decreased synergism. The chosen system demonstrated a very good analytical figures of merit with differential pulse anodic stripping voltammetry and cyclic voltammetry transduction, showing lower limits of detection (0.24 ng mL-1, S/N = 3) for both isomers. The proposed sensor assures practical applications as disease biomarker, manifesting several diseases at very ultra-trace level.

Molecularly imprinted polymer-based solid-phase microextraction fiber coupled with molecularly imprinted polymer-based sensor for ultratrace analysis of ascorbic acid.

Clinical manifestations owing to ascorbic acid deficiency demand an easy-to-use, rapid, robust and inexpensive technique, which can measure serum ascorbic acid at ultratrace level to attend the problem of hypovitaminosis C and acute cases of scurvy. In the present work, a novel molecularly imprinted polymer (MIP)-coated solid-phase microextraction (SPME) fiber that could be coupled to a complementary MIP-sensor was prepared with ascorbic acid as a template molecule. The characteristics and applications of this fiber were investigated. The same MIP receptor for both SPME and the corresponding sensor was able to enhance the preconcentration of analyte substantially so as to attain the stringent level of sensitivity in highly diluted aqueous, blood serum and pharmaceutical samples. The extraction yield of ascorbic acid (AA) with the MIP-coated fiber was found to be quantitative (detection limit 0.0396 ng mL(-1), RSD=2.3%, S/N=3) in aqueous samples without any problem of non-specific false positive results and cross-reactivity.

One-by-one imprinting in two eccentric layers of hollow core-shells: Sequential electroanalysis of anti-HIV drugs.

Double layered one-by-one imprinted hollow core-shells@ pencil graphite electrode was fabricated for sequential sensing of anti-HIV drugs. For this, two eccentric layers were developed on the surface of vinylated silica nanospheres to obtain double layered one-by-one imprinted solid core-shells. This yielded hollow core-shells on treatment with hydrofluoric acid. The modified hollow core-shells (single layered dual imprinted) evolved competitive diffusion of probe/analyte molecules. However, the corresponding double layered one-by-one imprinted hollow core-shells (outer layer imprinted with Zidovudine, and inner layer with Lamivudine) were found relatively better owing to their bilateral diffusions into molecular cavities, without any competition. The entire work is based on differential pulse anodic stripping voltammetry at double layered one-by-one imprinted hollow core-shells. This resulted in indirect detection of electro inactive targets with limits of detection as low as 0.91 and 0.12 (aqueous sample), 0.94 and 0.13 (blood serum), and 0.99 and 0.20 ng mL-1 (pharmaceutics) for lamivudine and zidovudine, respectively in anti-HIV drug combination.

Molecularly imprinted polymer-based solid-phase extraction combined with molecularly imprinted polymer-based sensor for detection of uric acid.

The development of an easy-to-use, rapid, robust and inexpensive technique is required which can measure the basal concentration of uric acid (UA) lower than 1.0 x 10(-7)M ( approximately 0.017 mgL(-1)) in biological samples to attend the problem of hypouricemia. In the present work an artificial receptor for UA, silica gel-bonded molecularly imprinted polymer (MIP), was used as a sorbent for molecularly imprinted solid-phase extraction (MISPE) in column chromatography. The use of a sensor based on a MIP-modified hanging mercury drop electrode (HMDE), as reported from our laboratory, could estimate UA with detection limit as low as 0.024 mgL(-1) under the optimized conditions of differential pulse, cathodic stripping voltammetric (DPCSV) measurement. However, in the current investigation, with the use of the combination of MISPE followed by detection with a MIP-based HMDE sensor, the minimum detectable concentration could go down to 0.0008 mgL(-1) (RSD=0.63%, S/N=3). The same MIP receptor for both MISPE and the corresponding sensor was able to enhance the preconcentration of analyte substantially so as to attain the desired level of sensitivity; and that to without any interference (cross-reactivity) from other structurally related analogues including the major interferent like ascorbic acid prevalent in the aqueous environment of biological samples.

Development of surface imprinted nanospheres using the inverse suspension polymerization method for electrochemical ultra sensing of dacarbazine.

A new ultra sensing molecularly imprinted polymer beads modified pencil graphite electrode was fabricated, with the help of the inverse suspension polymerization technique, for ascertaining the adequate supplementation of dacarbazine in the cancer treatment. The inverse suspension polymerization technique was beneficial in obtaining surface imprinted polymer-based electrocatalytic nanospheres with narrow size distribution. These nanospheres were found to be superior to the corresponding microspheres and planar films, in terms of electrode kinetics and sensitivity, with the differential pulse anodic stripping voltammetric transduction. Herein, multiwalled carbon nanotubes functionalized ester links were invoked in between the imprinted nanospheres and the pencil graphite electrode surface to secure a stable coating and better electrodics. The proposed electrochemical sensor showed the imprinting factor and the analyte adsorption coefficient as high as 24.3 and 1.06 × 109 L mol-1, respectively. Furthermore, 16-fold and 4-fold faster electron transfer kinetics were observed with the imprinted nanospheres than the corresponding imprinted planar film and the microspheres based electrodes, respectively. The limits of detection [0.02 (aqueous), 0.02 (plasma), 0.01 (urine), and 0.03 ng mL-1 (pharmaceutics), (3σ, RSD ≤ 0.23%)] of dacarbazine, realized with the imprinted polymer nanospheres, were free from any cross-reactivity and false-positive complications in aqueous, blood plasma, urine, and pharmaceutical samples.

Synthesis of fullerene (C60-monoadduct)-based water-compatible imprinted micelles for electrochemical determination of chlorambucil.

A novel water-compatible C60-monoadduct based imprinted micelles was synthesized by the self-assembly of vinylic-C60-monoadduct with sodium dodecylsulfate micellar system, in the presence of chlorambucil as a model template (anticancer drug). After template retrieval with acetonitrile, these imprinted micelles were immobilized at the surface of ionic liquid decorated carbon ceramic electrode. Herein, C60-monoadduct (the head group of micelle) actually served as a nanomediator for electronic transmission across multiple interfaces. Such modification induced electrocatalytic characteristics by decreasing analyte oxidation overpotential and thereby augmented the electrode kinetics. Consequently, the differential pulse anodic stripping transduction was realized to be approximately four-fold as compared to the corresponding electrode modified without C60-monoadduct. This revealed the potential role of fullerene as nanomediator in the signal transduction. Herein, ionic liquids facilitated electron transport by two-fold without any interfacial barrier through carbon layers than that realized with modified ceramic electrodes made in the absence of ionic liquids. A perfect linearity in the current-concentration profile under optimal conditions was observed for the analyte concentration in the range 1.47-247.20ngmL-1, with the detection limits to the tune of 0.36ngmL-1 (S/N=3) in aqueous and real samples.

Development of molecularly imprinted polymer nanoarrays of N-acryloyl-2-mercaptobenzamide on a silver electrode for ultratrace sensing of uracil and 5-fluorouracil.

The present work describes a new, simple and easy method for the generation of novel molecularly imprinted polymer-based nanoarrays with uracil and 5-fluorouracil as template(s) on the surface of a silver electrode. The procedure involved electrochemical etching of silver-wire to develop nanopores on its tip. In these nanopores, a prepolymer mixture with template(s) was filled-in via spin coating and subjected to free radical thermal polymerization. The bulk polymer and polymer film characteristics were investigated using Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and atomic force microscopy. The prepolymerization complex stoichiometry involved one template molecule and two molecules of the N-acryloyl-2-mercaptobenzamide functional monomer. The molecular structure of this complex was thermodynamically optimized via density functional theory at the MP2/6-31+G(d,p) level. The nanoarrays, vertically tethered imprinted polymer brushes with embedded carbon nanotubes, helped enhancing the surface area of the electrode. This drastically facilitated unhindered vertical diffusion with selective binding of uracil and 5-fluorouracil and their sensitive analysis using differential pulse anodic stripping voltammetry, with detection limits as low as 0.50 and 0.33 ng mL-1 (S/N = 3), respectively. The proposed nanoscale electro-chemical sensor was also validated with the complex matrices of blood plasma and pharmaceutics which assured reliable results, without any matrix effect, cross-reactivity, and false-positives. The large therapeutic range of the test analyte (uracil 1.49-278.76 ng mL-1, 5-fluorouracil 1.33-401.15 ng mL-1), demonstrating a perfect linearity (R2 = 0.98) with the improved voltammetric response, merits special significance for the primitive diagnosis of several chronic diseases, in clinical settings, without any sample pretreatment.

Double-ion imprinted polymer @magnetic nanoparticles modified screen printed carbon electrode for simultaneous analysis of cerium and gadolinium ions.

A typical, reproducible, and rugged screen printed carbon electrode, modified with dual-ion imprinted beads, was fabricated employing the "surface grafting from" approach. For this, the acyl chloride functionalized magnetic nanoparticles were first immobilized and chemically attached with a typical functional monomer (but-2-enedioic acid bis-[(2-amino-ethyl)-amide]) on the electrode surface. This was subsequently subjected to the thermal polymerization in the presence of template ions (Ce(IV) and Gd(III)), cross-linker (ethylene glycol dimethacrylate), initiator (AIBN), and multiwalled carbon nanotubes. The modified sensor was used for the simultaneous analysis of both template ions in aqueous, blood serum, and waste-water samples, using differential pulse anodic stripping voltammetry which revealed two oxidation peaks for respective templates with resolution as much as 950 mV, without any cross reactivity, interferences and false-positives. The detection limits realized by the proposed sensor, under optimized conditions, were found to be as low as 0.07 ng mL(-1) for Ce(IV) and 0.19 ng mL(-1) for Gd(III) (S/N=3) that could eventually be helpful for lanthanide estimation at stringent levels.

Trace analysis of 1,10-phenanthroline based herbicide in water and soil samples.

A sensitive analytical procedure for diquat herbicide viz. 5,6-dihydropyrazino[1,2,3,4-lmn]-1,10-phenanthrolinium dichlorides in drinking water and soil samples, using differential pulse adsorptive stripping voltammetry (DPAdSV) has been developed. This involved the adsorptive accumulation of a diquat herbicide onto a hanging mercury drop electrode [accumulation potential -0.8 V vs Ag/AgCl, accumulation time 60 s, pH 7.0, ionic strength 0.1 M] for DPAdSV measurement. The detection limit for diquat herbicide was as low as 0.034 micromol L(-1) level (S/N 2, RSD 2.9%) at an accumulation time of 60 s.

An insulin monitoring device based on hyphenation between molecularly imprinted micro-solid phase extraction and complementary molecularly imprinted polymer-sensor.

Molecularly imprinted micro-solid phase extraction fiber was developed by modifying molecularly imprinted polymer film on the surface of silica fiber exploring "grafting via surface attached monomer" (method I) and "grafting via sol-gel" (method II) approaches. The latter approach was found to be inferior to the former one in terms of the sensitivity of insulin detection [method I, LOD=0.009ngmL(-1); method II, LOD=0.064ngmL(-1), RSD=1.21%]. Notably, either of the techniques, molecularly imprinted micro-solid phase extraction or complementary sensor, was found to be incompetent to monitor the stringent level of insulin in the real samples. However, the combination of these techniques has been found quite suitable for achieving the high detection sensitivity of ultra-trace insulin in human blood serum and Huminsulin injection, without any non-specific (false-positives) contributions. The proposed hyphenated device could serve as a possible marker for risk of developing type 2 diabetes mellitus and diabetic coma due to insulin resistance in human beings.

Doubly imprinted polymer nanofilm-modified electrochemical sensor for ultra-trace simultaneous analysis of glyphosate and glufosinate.

A rapid, selective, and sensitive double-template imprinted polymer nanofilm-modified pencil graphite electrode was fabricated for the simultaneous analysis of phosphorus-containing amino acid-type herbicides (glyphosate and glufosinate) in soil and human serum samples. Since both herbicides respond overlapped oxidation peaks and only glyphosate is prone to nitrosation, n-nitroso glyphosate and glufosinate were used as templates for obtaining the well-resolved quantitative differential pulse anodic stripping voltammetric peaks on the proposed sensor. Toward sensor fabrication, a nano-structured polymer film was first grown directly on the electrode via initial immobilization of gold nanoparticles at its surface. This was followed by linking of monomeric (N-methacryloyl-l-cysteine) molecules through S-Au bonds. Subsequently, these molecules were subjected to free radical polymerization, in the presence of templates, cross linker, initiator, and multiwalled carbon nanotubes as pre-polymer mixture. The modified sensor observed wide linear ranges (3.98-176.23 ng mL(-1) and 0.54-3.96 ng mL(-1)) of simultaneous analysis with detection limits as low as 0.35 and 0.19 ng mL(-1) (S/N=3) for glyphosate and glufosinate, respectively, in aqueous samples. The respective oxidation peak potentials of both analytes were found to be substantially apart by 265 mV. This enabled the simultaneous determination of one target in the presence of other, without any cross reactivity, interferences, and false-positives, in real samples.

Molecularly imprinted micro solid-phase extraction technique coupled with complementary molecularly imprinted polymer-sensor for ultra trace analysis of epinephrine in real samples.

A simple hyphenation approach was adopted to obtain a new molecularly imprinted micro solid-phase extraction fiber (as a selective extraction tool) and complementary molecularly imprinted polymer coated pencil graphite electrode (as a detection tool) for the selective and sensitive analysis of epinephrine, which is a disease biomarker prevalent at ultra trace level in biological fluids. In both extraction and detection processes, the functionalized multiwalled carbon nanotubes (CNT-mers) were preferred to multiwalled carbon nanotubes (unmodified) in order to obtain a stable homogeneously dispersed imprinted polymer matrix of better electroconductivity and adsorptive characteristics. The hyphenation of both tools helped dual pre-concentration of epinephrine so as to achieve the stringent limit [limit of detection: 0.002 ng mL(-1), S/N=3] of clinical detection, without any problems of non-specific contributions and cross-reactivity.

Molecular structure, vibrational spectra and quantum chemical MP2/DFT studies toward the rational design of hydroxyurea imprinted polymer.

In this study, both experimental and theoretical vibrational spectra of template (hydroxyurea, HU), monomer (N-(4,6-bisacryloyl amino-[1,3,5] triazine-2-yl-)-acryl amide, TAT), and HU-TAT complexes were compared and these were respectively found to be in good agreement. Binding energies of HU, when complexed with different monomers, were computed using second order Moller Plesset theory (MP2) at 6-311++G(d,p) level both in the gas as well as solution phases. HU is an antineoplastic agent extensively being used in the treatment of polycythaemia Vera and thrombocythemia. It is also used to reduce the frequency of painful attacks in sickle cell anemia. It has antiretroviral property in disease like AIDS. All spectral characterizations were made using Density Functional Theory (DFT) at B3LYP employing 6-31+g(2d,2p) basis set. The theoretical values for (13)C and (1)H NMR chemical shifts were found to be in accordance with the corresponding experimental values. Of all different monomers studied for the synthesis of molecularly imprinted polymer (MIP) systems, the monomer TAT (2 mol) was typically found to have a best binding score requisite for complexation with HU (1 mol) at the ground state.