Commercial Compact Disk Research Articles

Low-Cost and Desktop-Fabricated Biosensor for Rapid and Sensitive Detection of Circulating D-Dimer Biomarker

Disposable point-of-care biomedical applications demand low-cost biosensing systems that can provide rapid detection with accessible fabrication requirements and user-friendly operation. Here, we present an easy-to-operate and cleanroom-free desktop-fabricated biosensor that is capable of reliable detection for human D-dimer biomarkers on-site. Interdigitated electrodes are used as the biosensor, and they are fabricated using commercial compact discs and home-made gadgets. The compact disc-based electrode arrays are patterned by wet-etching and followed by electroplating of polypyrrole (PPy). The nano-porous structures of PPy enhance the immobilization of protein probe on the electrode surface. The sensor performance is further enhanced by the ac electrokinetics (ACEK) capacitive sensing method. ACEK capacitive sensing induces ACEK effects that direct analytes toward the electrode surfaces, significantly promoting probe-target binding. Our sensor can quantitatively detect D-dimer biomarkers in 1 min with a limit of detection of 1 pg/mL. In contrast, Nyquist or Bode plots can only qualitatively distinguish positive and negative samples. Furthermore, the total cost of each test, together with the lithography material and compact disk, is only around U.S. $1, and it is acceptable to be disposable. The sensitive device yields wide-ranging and significant advantages for biomedical and lab-on-a-chip applications for undeveloped areas.

Transforming a Compact Disk into a Simple and Cheap Photocatalytic Nanoreactor.

A commercial compact disk has been converted into an effective photocatalytic nanoreactor by depositing a catalyst layer inside the nanochannels by means of an electrophoretic method. The resultant device has been tested for water splitting, obtaining a high yield of hydrogen at an unbeatable low cost.

Biopatterning of antibodies on poly(pyrrole)-nanowires using nanocontact printing: Surface characterization

A highly performant patterning of antibodies using poly(pyrrole) nanowires (PPy-NWs) was devised on thermoplastic surfaces based on silane derivatives. The PPy-NWs were fabricated employing nanocontact printing and controlled chemical polymerization (nCP-CCP) on poly(ethylene terephthalate), cyclic olefin copolymer, poly(ethylene 2,6-naphthalate), and polyimide. The technique used a commercial compact disk as a template (mold) to produce nanopatterned polydimethylsiloxane stamps. The nanopatterned stamp was then employed to print PPy-NWs. The printing technique permits to control PPy-NW size and shape. The dimensions of the printed PPy-NWs were: 785 ± 1.5 nm (width), 174 ± 2.1 nm (height), and a separation between wires of 540 ± 1.2 nm. The printing process and the surface properties of the PPy-NWs pattern were successfully characterized by scanning electron microscopy and atomic force microscopy. Biopatterning was completed by the chemical immobilization of the specific anti-human interleukin-10 monoclonal antibody on PPy-NW using gluteraldehyde. The biocomposite was tested using qualitative immunocytokine bioassay, which is of great importance for early stage cancer detection. For that purpose, fluorescent imaging was used to certify the immunodetection of the recombinant human interleukin-10. The biopatterning technology provides a simple, low cost and one step procedure. Undoubtedly, this new technology will impact and provide an alternative to the current techniques applied for bioengineering and nanopatterning.

Large area in situ fabrication of poly(pyrrole)-nanowires on flexible thermoplastic films using nanocontact printing

Highly efficient nano-engineering tools will certainly revolutionize the biomedical and sensing devices research and development in the years to come. Here, we present a novel high performance conducting poly(pyrrole) nanowires (PPy-NW) patterning technology on thermoplastic surfaces (poly(ethylene terephthalate (PETE), poly(ethylene 2,6-naphthalate (PEN), polyimide (PI), and cyclic olefin copolymer) using nanocontact printing and controlled chemical polymerization (nCP-CCP) technique. The technique uses a commercial compact disk as a template to produce nanopatterned polydimethylsiloxane (PDMS) stamps. The PDMS nanopatterned stamp was applied to print the PPy-NWs and the developed technology of nCP-CCP produced 3D conducting nanostructures. This new and very promising nanopatterning technology was achieved in a single step and with a low cost of fabrication over large areas.

Pyrolysis and catalytic pyrolysis as a recycling method of waste CDs originating from polycarbonate and HIPS

Pyrolysis appears to be a promising recycling process since it could convert the disposed polymers to hydrocarbon based fuels or various useful chemicals. In the current study, two model polymers found in WEEEs, namely polycarbonate (PC) and high impact polystyrene (HIPS) and their counterparts found in waste commercial Compact Discs (CDs) were pyrolysed in a bench scale reactor. Both, thermal pyrolysis and pyrolysis in the presence of two catalytic materials (basic MgO and acidic ZSM-5 zeolite) was performed for all four types of polymers. Results have shown significant recovery of the monomers and valuable chemicals (phenols in the case of PC and aromatic hydrocarbons in the case of HIPS), while catalysts seem to decrease the selectivity towards the monomers and enhance the selectivity towards other desirable compounds.

Submicron Size Patterned Nickel Soft Lithographic Masters Using Aluminium Template

Nickel masters are widely used to produce surface relief grating like patterned antireflection coatings of polysiloxane material by simple embossing process. In the present work, patterned nickel master was prepared by using aluminium template, which is a foil peeled off from the commercial compact disk. Nickel was deposited using Watts nickel bath by pulsed electrodeposition for different relaxation times on patterned aluminium template. The deposition led to the transfer of patterns of aluminium replica to the nickel deposit. After deposition, the aluminium template was etched out chemically. Observation under an optical microscope showed that the obtained pattern was highly homogenous only for Ton = 0.1 ms, Toff = 0.9 ms duty cycles as compared with other ‘on’ and ‘off’ times of pulse cycles. This simple single step cost effective nickel master can serve as stamps for the subsequent embossing process. The preparation conditions and its salient features are discussed in this paper in detail.

A Modified Consumer Inkjet for Spatiotemporal Control of Gene Expression

This paper presents a low-cost inkjet dosing system capable of continuous, two-dimensional spatiotemporal regulation of gene expression via delivery of diffusible regulators to a custom-mounted gel culture of E. coli. A consumer-grade, inkjet printer was adapted for chemical printing; E. coli cultures were grown on 750 µm thick agar embedded in micro-wells machined into commercial compact discs. Spatio-temporal regulation of the lac operon was demonstrated via the printing of patterns of lactose and glucose directly into the cultures; X-Gal blue patterns were used for visual feedback. We demonstrate how the bistable nature of the lac operon's feedback, when perturbed by patterning lactose (inducer) and glucose (inhibitor), can lead to coordination of cell expression patterns across a field in ways that mimic motifs seen in developmental biology. Examples of this include sharp boundaries and the generation of traveling waves of mRNA expression. To our knowledge, this is the first demonstration of reaction-diffusion effects in the well-studied lac operon. A finite element reaction-diffusion model of the lac operon is also presented which predicts pattern formation with good fidelity.

Use of polystyrene spin-coated compact discs for microimmunoassaying

The analytical potential of polystyrene (PS) spin-coated modified compact discs (CDs) surface as platforms for the development of microarray immunoassays is presented. The surface maintained the optical characteristics of compact discs, obtaining a transparent and smooth film polymer of 70 nm thickness, the track being read ( λ 780 nm) without errors in a commercial CD reader/writer. The analytical capability of the methodology was demonstrated through an analysis of a neurotoxic compound (2560 spots per disc), reaching 0.08 μg L −1 as limit of detection. These figures demonstrate the enormous potential of using PS spin-coated compact discs in combination with CD players as an easy-to-operate and portable device to develop lab-on-a-disc analytical applications.

Measurement of Cantilever Displacement Using a Compact Disk/Digital Versatile Disk Pickup Head

We use the optical pickup head of a commercial compact disk (CD)/digital versatile disk (DVD) read only memory (ROM) drive to detect the vertical displacement of micro fabricated cantilever in atomic force microscopy (AFM). Both the contact and AC modes of AFM are demonstrated. The single atomic steps of graphite can be resolved, indicating that atomic resolution in the vertical displacement detection can be achieved with this new setup. The low cost, compact size, and the light weight of CD/DVD optical pickups may offer new advantages in future AFM designs.

Effect of the Finite Element Meshing for Designing Plastic Pieces

The objective of this work was to modify the simulation mesh model characteristics (critical areas evaluation, mesh density, and elements size) of a commercial compact disk (CD) case by using computer-aided design (CAD) and computer aided engineer (CAE) software. The designing process was carried out by studying the geometry and dimensions of the three pieces (cover, holder, and base) that form commercial and optimized CD cases.The mesh model was obtained using 3D (three dimensional) modeler software and the simulation results were obtained using a simulation program typically used for the injection-molding process. The exposed designs were evaluated and different mesh model characteristics were established. The filling time, cycle time, and residual stress concentration seemed to be influenced by the nodes number model. An analysis of the results of the simulations showed remarkable differences when a high number of nodes in the mesh model were used.

Centrifuge-Based Fluidic Platforms

In this paper, centrifuge-based microfluidic platforms are reviewed and compared with other popular microfluidic propulsion methods. The underlying physical principles of centrifugal pumping in microfluidic systems are presented and the various centrifuge fluidic functions such as valving, decanting, calibration, mixing, metering, heating, sample splitting, and separation are introduced. Those fluidic functions have been combined with analytical measurement techniques such as optical imaging, absorbance and fluorescence spectroscopy and mass spectrometry to make the centrifugal platform a powerful solution for medical and clinical diagnostics and high-throughput screening (HTS) in drug discovery. Applications of a compact disk (CD)-based centrifuge platform analyzed in this paper include two-point calibration of an optode-based ion sensor, an automated immunoassay platform, multiple parallel screening assays, and cellular-based assays. The use of modified commercial CD drives for high-resolution optical imaging is discussed as well. From a broader perspective, we compare technical barriers involved in applying microfluidics for sensing and diagnostics as opposed to applying such techniques to HTS. The latter poses fewer challenges and explains why HTS products based on a CD fluidic platform are already commercially available, while we might have to wait longer to see commercial CD-based diagnostics.

Indoor radon detected by compact discs

An approach for a precise retrospective assessment of the indoor radon exposure using commercial compact discs (CDs) is proposed. It is based on the remarkable radon absorption and α track-etch properties of polycarbonate — the basic material of the CDs. The experimental results indicate that the useful range of this approach is able to cover practically the entire range of indoor 222Rn concentrations.