Editorial [Hot Topic:Supramolecular Devices for the High-Throughput Screening of Drugs,Nutrients and Metabolites in Postgenomic Era (Part 3) (Guest Editor: Grzegorz Bazylak)]

The growing need for microfluidic systems in high throughput screening (HTS) urgently demands the development of compatible detection systems, especially for the analysis of non-labeled and ionizable analytes. Direct detection employing electrochemical processes offers remarkable advantages such as reduced cost, low power requirements, enhanced portability, independence of sample turbidity, subnanomolar sensitivity, reproducibility, and compatibility with micromachining and microfabrication procedures. More than 70% of current drugs are ionizable under physiological conditions and have the potential to be measured using electrochemical detection. The papers in Part 3 of this special issue of Combinatorial Chemistry & High Throughput Screening summarize and highlight some recent advances, directions and key concepts in the development of new supramolecular electrode materials, ion recognition modes, detection schemes, operational principles, applications and future prospects for electrochemical HTS devices and sensors. The review by Uslu and Ozkan opening this issue presents the status and recent achievements in the use of native and chemically modified solid noble metal and carbon nanotube electrodes for HTS of drugs and pharmacologically active compounds. In addition, the review by Gulaboski et al. describes the use of new four-electrode and three-phase electrode voltammetry at the interface of immiscible electrolyte solutions mimicking biomembrane systems which enables precise determination of unknown standard partition coefficients for ionized drugs-of-abuse, peptides, nutrients, and examples of ubiquitous environmental pollutants. Similarly, Ganjali et al., review the use of podand, macrocycle or transition metal complexed Schiff bases as highly selective ionophores in the construction of disposable electrodes for HTS of inorganic cations and anions, as well as ionizable drugs and nutrients. In the minireview by Wang et al., recent progress is discussed concerning the sensitive and specific electrochemical detection of drugs and their metabolites under the continuous flow conditions of HPLC or ultra-fast flow-injection analysis. The practical implementation and unique properties of lipophilic podand ionophore supported potentiometric detection in the construction of DNA sensitive arrays coupled with HPLC is reported in the research paper by Nagels et al. In addition, the construction and characteristics of lipophilic calix[4]resorcinarene based potentiometric sensor enabling selective determination of positional isomers of phenylenediamine type endocrine disrupting agents and allergens are reported in the paper by Radecki et al. Spectacular examples of selective electrochemical determination of drugs used in mono and combined therapies of metabolic, degenerative and infectious human diseases such as a non-insulin-dependent diabetes mellitus, beginning prostatic hyperplasia, atherosclerosis, rheumatoid arthritis, and ascariasis are described in the series of research papers by Gupta et al., Dogan-Topal et al., Wang et al., and Aboul-Enein et al. Innovative potentiometric and voltammetric procedures were developed and described in these research papers using a boron doped diamond, a carbon nanotubes and liquid membrane electrodes. By reducing the size of such working electrodes, it will be possible to enhance their performance and sensitivity even further. Thus, it is quite reasonable to say that complete self-contained HTS microsystems equipped with electrochemical detection may be realized soon through an on-chip and proteochip integration of the potentiostatic circuitry with supramolecular versions of nanovalves, switchers, transducers, digital multiplexers, logic networks, sequential and combinational circuits as well as memory that mimic the operation of currently used semiconductor logic gates. Hoping that our publishing efforts will help transform such promising views into reality, I would like to extend my grateful thanks, as the Guest Editor of this special issue of Combinatorial Chemistry & High Throughput Screening, to all authors who kindly contributed in all three parts of this exceptional project.