Flexible and disposable gold nanoparticles-N-doped carbon-modified electrochemical sensor for simultaneous detection of dopamine and uric acid
Authors: Patil, Aniruddha B.; Zheng, Chuanbao; Ma, Liyun; Wu, Ronghui; Mengane, Sharwari K.; Zhang, Yifan; Liu, Xiaotian; Meng, Zhaohui; Zhang, Wenli; Xu, Zijie; Chen, Caifeng; Huang, Jiani; Liu, Xiang Yang
Catalytic and electrocatalytic applications of supported metal nanoparticles are hindered due to an aggregation of metal nanoparticles and catalytic leaching under harsh operations. Hence, stable and leaching free catalysts with high surface area are extremely desirable but also challenging. Here we report a gold nanoparticles-hosted mesoporous nitrogen doped carbon matrix, which is prepared using bovine serum albumin (BSA) through calcination. BSA plays three roles in this process as a reducing agent, capping agent and carbon precursor, hence the protocol exhibits economic and sustainable. Gold nanoparticles at N-doped BSA carbon (AuNPs@NBSAC)-modified three-electrode strip-based flexible sensor system has been developed, which displayed effective, sensitive and selective for simultaneous detection of uric acid (UA) and dopamine (DA). The AuNPs@NBSAC-modified sensor showed an excellent response toward DA with a linear response throughout the concentration range from 1 to 50 mu M and a detection limit of 0.05 mu M. It also exhibited an excellent response toward UA, with a wide detection range from 5 to 200 mu M as well as a detection limit of 0.1 mu M. The findings suggest that the AuNPs@NBSAC nanohybrid reveals promising applications and can be considered as potential electrode materials for development of electrochemical biosensors.
Prozone phenomenon observed in indirect immunofluorescence assay by antibodies against neuronal antigens
JOURNAL OF NEUROIMMUNOLOGY
Authors: Mathai, Annamma; Panicker, Suprabha; Kannoth, Sudheeran; Anandakuttan, Anandkumar
A marked prozone effect was observed in indirect immunofluorescence with human sera and human cere-brospinal fluid in two clinical cases involving breast carcinoma with paraneoplastic neuronal antibodies, and anti N-methyl-D-aspartic acid (NMDA) receptor antibodies. Anti-Yo antibodies and anti-NMDA antibodies were not detectable under high concentrations (1:10 serum dilution and neat CSF respectively) but showed a true effect when sufficiently diluted at 1:80 and 1:5 respectively. This paper demonstrates that prozone effects have their occurrences in indirect immunofluorescence, and clinicians and laboratory technicians should be wary of its implications during screening of autoantibody markers in neurological diseases.