“…The enriched functional groups can interact in an ionic, covalent or non-covalent manner, so that in principle they provide the highest extraction efficiency of biomolecules per unit area . In recent years, the functionalized GO has been exploited to fabricate biosensors for drug delivery Zhang et al, 2010a), bioimaging in living cells Sun et al, 2008), the detection of cancer cell (Tao et al, 2013), glucose (Song et al, 2010), DNA Gao et al, 2014), enzyme (Zhang et al, 2010b), protein , peptides (Han et al, 2010), and cellulose and lignin .…”