A labchip for highly selective and sensitive electrochemiluminescence detection of Hg2+ ions in aqueous solution employing integrated amorphous thin film diodes

• Published in: Microsystem technologies Vol. 14; no. 4-5; pp. 589 - 599
• Main Authors: Schäfer, Heiko, Lin, Hengwei, Schmittel, Michael, Böhm, Markus
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.04.2008; Springer
• Subjects: Applied sciences; Electronics; Electronics and Microelectronics; Engineering; Exact sciences and technology; Instrumentation; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Mechanical Engineering; Mechanical engineering. Machine design; Mechanical instruments, equipment and techniques; Microelectronic fabrication (materials and surfaces technology); Micromechanical devices and systems; Nanotechnology; Physics; Precision engineering, watch making; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Technical Paper; Reverse Bias Voltage; Application Specific Integrate Circuit; Transparent Conductive Oxide; Dark Current Density; Bipy; Amorphous material; Vibration; Measurement sensor; Amorphous state; Chemical sensor; Experimental study; Thin film; High sensitivity; Linearity; Silicon; Aqueous solution; Monolithic integrated circuit; p i n diode; Nanotechnology
• ISSN: 0946-7076; 1432-1858
• DOI: 10.1007/s00542-007-0439-5

An electrochemiluminescence (ECL) based detection of Hg 2+ ions using a novel monolithically integrated labchip technology has been developed. The combination of a chemical sensor molecule, the azacrown ether appended trisphenanthroline ruthenium(II) complex 1 , and an amorphous silicon based pin-diode detects an exceptionally low concentration of 66 nM according to a device current of 1.85 pA, respectively. To support a high sensitivity, fluid volumes of 1.2 or 1.8 nL in the designed measuring cells are investigated by an amorphous silicon based pin-diode at a constant flow rate of 1 μL min −1 . The working electrode area can be specified for both cells to 0.06 or 0.09 mm 2 according to a photosensitive detector area of 400 or 500 μm in diameter. Corresponding to the distance between the monolithic integrated polymer based microcapillary and the sensing pin-diode layers of ∼150 μm the detector solid angle was calculated to 73.3°. The fabrication methodology and the experimental details are presented. Furthermore, performance metrics including diode characteristics, detection limit, transient current behavior, dynamic range, and linearity are reported. Additionally, the chemical structure, the ECL response towards different metal ions, and the relationship between ECL intensity of 1 and the concentration of Hg 2+ ions are shown.