Journal of Pharmaceutical and Biomedical Analysis 137 (2017) 163–169 Contents lists available at ScienceDirect Journal of Pharmaceutical and Biomedical Analysis journal homepage: www.elsevier.com/locate/jpba Impedimetric nanostructured genosensor for detection of schistosomiasis in cerebrospinal fluid and serum samples Giselle S. Santos a , Cesar A.S. Andrade b , Igor S. Bruscky c , Leandro B. Wanderley d , Fabio L. Melo e , Maria D.L. Oliveira a,b,∗ a Programa de Pós-Graduac ¸ ão em Ciências Biológicas, Universidade Federal de Pernambuco, 50670-901 Recife, PE, Brazil b Departamento de Bioquímica, Universidade Federal de Pernambuco, 50670-901 Recife, PE, Brazil c School of Medicine, University of Pernambuco, Recife, Pernambuco, Brazil d Aggeu Magalhaes Research Center/FIOCRUZ, Recife, Pernambuco, Brazil e Laboratório de Doenc ¸ as Transmissíveis, Centro de Pesquisas Aggeu Magalhães, 50670-420 Recife, PE, Brazil a r t i c l e i n f o Article history: Received 26 November 2016 Received in revised form 12 January 2017 Accepted 14 January 2017 Available online 20 January 2017 Keywords: Biosensors Schistosomiasis DNA Cyclic voltammetry Impedance spectroscopy Metal nanoparticles a b s t r a c t Schistosomiasis is a neglected disease closely related to the low levels of social development and a serious public health problem. In this work, we performed an electrochemical detection of Schistosoma mansoni DNA with a self-assembled monolayer of mercaptobenzoic acid (MBA) immobilizing nanostruc- tures composed of gold nanoparticles (AuNPs) and magnetite nanoparticles (Fe 3 O 4 NPs). Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were used to monitor the hybridization pro- cess. MBA-Fe 3 O 4 NPs-AuNPs-DNAprobe system reveals an effective electrochemical response indicating the surface modification. The proposed biosystem was capable to recognize specific nucleotide sequence of S. mansoni present in cerebrospinal fluid (CFS) and serum samples at different genome DNA concen- trations. The biorecognition resulted in an increase in the electron transfer resistance and a decrease of the current peaks at higher DNA concentrations during electrochemical measurements. The developed platform showed a DNA detection limit of 0.781 and 0.685 pg L −1 for serum and CFS, respectively. There- fore, the obtained biosensor can be considered as a useful tool for specific detection of S. mansoni at low concentrations in various biological fluids. © 2017 Elsevier B.V. All rights reserved. 1. Introduction Schistosomiasis is an important parasitic disease for public health caused by helminth Schistosoma mansoni [1], which can be found in many tropical regions of the globe [2]. Some studies have reported six to seven million people affected in Brazil [3,4] with higher prevalence in Northeast states [2] and Southeast states [5,6]. A severe form of S. mansoni is the ectopic schistosomiasis that can manifest in different ways, especially involving the nervous sys- tem [7]. In these infections, spinal cord is more frequently affected than the brain [8]. The early treatment of the disease is essential for a good prognosis and preventing indiscriminate use of drugs by patients. Therefore, it is necessary the development of afford- able diagnostic techniques with high sensibility and specificity [9]. Schistosomiasis diagnosis is based on the analysis of faecal sam- ∗ Corresponding author at: Departamento de Bioquímica, UFPE, 50670-901 Recife, PE, Brazil. E-mail address: m danielly@yahoo.com.br (M.D.L. Oliveira). ples and cerebrospinal fluid (CSF) for nervous system manifestation [7,10]. Some diagnostic tests such as ELISA, indirect fluorescence immunoassay, radioimmunoassay are also commonly used [11]. In general, diagnostic tests require expensive equipment and sup- plies, specialized technicians and are time-consuming [12]. The embolization of eggs during S. mansoni infection is the most important mechanism to reach the spinal cord. In addition, it is involved to endemic cases of neuroschistosomiasis in Brazil’s Northwest [13]. Diagnostic methods for spinal cord schistosomi- asis have low sensitivity and specificity. The definitive diagnosis of schistosomiasis is often a difficult process [14]. Therefore, an effective diagnosis is important, since early treatment can minimize sequelae [15,16]. Polymerase chain reaction (PCR) can be used to diagnose schis- tosomiasis in several biological samples [17], but its value in the CSF is still unknown. Some authors proposed the use of nested PCR to auxiliary the diagnosis of spinal cord schistosomiasis, in particular for cases with negative CSF serology [18]. However, further studies are needed to confirm its clinical use. http://dx.doi.org/10.1016/j.jpba.2017.01.031 0731-7085/© 2017 Elsevier B.V. All rights reserved.