Serum neurofilament light chain (NFL), a potential general
biomarker
for neurodegenerative diseases, is not specific enough to differentiate
neurodegenerative diseases from other brain diseases such as cerebral
thrombosis (CT). According to the importance of glycosylation in neurodegenerative
pathogenesis, the NFL glycosylation level (oNFL/tNFL), defined as
the ratio of glycosylated NFL (oNFL) to total NFL (tNFL), may be a
more effective index. The major challenge in serum oNFL/tNFL detection
is the ultra-low abundance of both NFL forms. In this paper, we achieved
a convenient one-step electrochemical quantitation of oNFL/tNFL based
on an interface-solution dual-path amplification strategy. Two amplified
electrochemical signalsthe reduction of Cu2+ from
adsorbed porous nanoparticles on the sensor interface and the reduction
of O2 from horseradish peroxidase-catalyzed H2O2 disproportionation in solutionwere adopted
to quantify tNFL and oNFL, respectively. The electrochemical sensor
displayed good sensitivity, selectivity, and reproducibility. The
dynamic range is 1–25 pg mL–1 for tNFL and
0.25–25 pg mL–1 for oNFL, respectively. By
analyzing the clinic serum samples, for the first time, our work provided
the abundance of oNFL in human serum and revealed that the oNFL/tNFL
is effective not only in differentiating three kinds of brain damage
patients from healthy people but also in differentiating neurodegeneration
from non-neurodegeneration CT patients. As a general biomarker, the
oNFL/tNFL is more specific than NFL, which is hoped to be a new and
valid indicator for the diagnosis, progression, prediction, and treatment
evaluation of neurodegenerative diseases.