TY - JOUR
T1 - Label-free electrical detection of DNA with a multi-spot LAPS
T2 - First step towards light-addressable DNA chips
AU - Wu, Chunsheng
AU - Bronder, Thomas
AU - Poghossian, Arshak
AU - Werner, Carl Frederik
AU - Bäcker, Matthias
AU - Schöning, Michael J.
PY - 2014/6
Y1 - 2014/6
N2 - A multi-spot (4 × 4 spots) light-addressable potentiometric sensor (MLAPS) consisting of an Al-p-Si-SiO2 structure has been applied for the label-free electrical detection of DNA (deoxyribonucleic acid) immobilization and hybridization by the intrinsic molecular charge for the first time. Single-stranded probe ssDNA molecules (20 bases) were covalently immobilized onto the silanized SiO2 gate surface. The unspecific adsorption of mismatch ssDNA on the MLAPS gate surface was blocked by bovine serum albumin molecules. To reduce the screening effect and to achieve a high sensor signal, the measurements were performed in a low ionic-strength solution. The photocurrent-voltage (I-V) curves were simultaneously recorded on all 16 spots after each surface functionalization step. Large shifts of I-V curves of 25 mV were registered after the DNA immobilization and hybridization event. In contrast, a small potential shift (∼5 mV) was observed in case of mismatch ssDNA, revealing good specificity of the sensor. The obtained results demonstrate the potential of the MLAPS as promising transducer platform for the multi-spot label-free electrical detection of DNA molecules by their intrinsic molecular charge.
AB - A multi-spot (4 × 4 spots) light-addressable potentiometric sensor (MLAPS) consisting of an Al-p-Si-SiO2 structure has been applied for the label-free electrical detection of DNA (deoxyribonucleic acid) immobilization and hybridization by the intrinsic molecular charge for the first time. Single-stranded probe ssDNA molecules (20 bases) were covalently immobilized onto the silanized SiO2 gate surface. The unspecific adsorption of mismatch ssDNA on the MLAPS gate surface was blocked by bovine serum albumin molecules. To reduce the screening effect and to achieve a high sensor signal, the measurements were performed in a low ionic-strength solution. The photocurrent-voltage (I-V) curves were simultaneously recorded on all 16 spots after each surface functionalization step. Large shifts of I-V curves of 25 mV were registered after the DNA immobilization and hybridization event. In contrast, a small potential shift (∼5 mV) was observed in case of mismatch ssDNA, revealing good specificity of the sensor. The obtained results demonstrate the potential of the MLAPS as promising transducer platform for the multi-spot label-free electrical detection of DNA molecules by their intrinsic molecular charge.
KW - DNA hybridization
KW - biosensors
KW - field-effect transistors
KW - label-free biosensing
KW - light-addressable potentiometric sensors
UR - https://www.scopus.com/pages/publications/84902385467
U2 - 10.1002/pssa.201330442
DO - 10.1002/pssa.201330442
M3 - 文章
AN - SCOPUS:84902385467
SN - 1862-6300
VL - 211
SP - 1423
EP - 1428
JO - Physica Status Solidi (A) Applications and Materials Science
JF - Physica Status Solidi (A) Applications and Materials Science
IS - 6
ER -