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Geerets B, Peeters M, van Grinsven B, Bers K, de Ceuninck W, Wagner P. Optimizing the thermal read-out technique for MIP-based biomimetic sensors: towards nanomolar detection limits. SENSORS (BASEL, SWITZERLAND) 2013; 13:9148-59. [PMID: 23863857 PMCID: PMC3758641 DOI: 10.3390/s130709148] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2013] [Revised: 06/27/2013] [Accepted: 07/10/2013] [Indexed: 12/02/2022]
Abstract
In previous work, the novel heat-transfer method (HTM) for the detection of small molecules with Molecularly Imprinted Polymers (MIP)-type receptors was presented. In this study we focus on optimization of this sensor performance, with as final aim to lower the detection limit by reducing the noise level. It was determined that the noise originates foremost from the power supply, which can be controlled by varying the PID parameters. Therefore, the effect of the individual parameters was evaluated by tuning P, I and D separately at a temperature of 37 °C, giving a first indication of the optimal configuration. Next, a temperature profile was programmed and the standard deviation of the heat-transfer resistance over the entire regime was studied for a set of parameters. The optimal configuration, P1-I6-D0, reduced the noise level with nearly a factor of three compared to the original parameters of P10-I5-D0. With the optimized settings, the detection of L-nicotine in buffer solutions was studied and the detection limit improved significantly from 100 nM to 35 nM. Summarizing, optimization of the PID parameters and thereby improving the detection limit is a key parameter for first applications of the HTM-method for MIP receptors in analytical research.
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Affiliation(s)
- Bram Geerets
- Institute for Materials Research, Hasselt University, Wetenschapspark 1, B-3590 Diepenbeek, Belgium; E-Mails: (B.G.); (B.G.); (K.B.); (W.D.C.); (P.W.)
| | - Marloes Peeters
- Institute for Materials Research, Hasselt University, Wetenschapspark 1, B-3590 Diepenbeek, Belgium; E-Mails: (B.G.); (B.G.); (K.B.); (W.D.C.); (P.W.)
- IMEC vzw, Division IMOMEC, Wetenschapspark 1, B-3590 Diepenbeek, Belgium
| | - Bart van Grinsven
- Institute for Materials Research, Hasselt University, Wetenschapspark 1, B-3590 Diepenbeek, Belgium; E-Mails: (B.G.); (B.G.); (K.B.); (W.D.C.); (P.W.)
- IMEC vzw, Division IMOMEC, Wetenschapspark 1, B-3590 Diepenbeek, Belgium
| | - Karolien Bers
- Institute for Materials Research, Hasselt University, Wetenschapspark 1, B-3590 Diepenbeek, Belgium; E-Mails: (B.G.); (B.G.); (K.B.); (W.D.C.); (P.W.)
- IMEC vzw, Division IMOMEC, Wetenschapspark 1, B-3590 Diepenbeek, Belgium
| | - Ward de Ceuninck
- Institute for Materials Research, Hasselt University, Wetenschapspark 1, B-3590 Diepenbeek, Belgium; E-Mails: (B.G.); (B.G.); (K.B.); (W.D.C.); (P.W.)
- IMEC vzw, Division IMOMEC, Wetenschapspark 1, B-3590 Diepenbeek, Belgium
| | - Patrick Wagner
- Institute for Materials Research, Hasselt University, Wetenschapspark 1, B-3590 Diepenbeek, Belgium; E-Mails: (B.G.); (B.G.); (K.B.); (W.D.C.); (P.W.)
- IMEC vzw, Division IMOMEC, Wetenschapspark 1, B-3590 Diepenbeek, Belgium
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Simultaneous determination of serotonin and creatinine in urine by combining two ultrasound-assisted emulsification microextractions with on-column stacking in capillary electrophoresis. J Sep Sci 2011; 35:436-44. [DOI: 10.1002/jssc.201100778] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2011] [Revised: 10/27/2011] [Accepted: 11/01/2011] [Indexed: 11/07/2022]
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Kema IP, de Vries EG, Muskiet FA. Clinical chemistry of serotonin and metabolites. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 2000; 747:33-48. [PMID: 11103898 DOI: 10.1016/s0378-4347(00)00341-8] [Citation(s) in RCA: 154] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Analyses of serotonin and other 5-hydroxyindoles, such as its precursor 5-hydroxytryptophan and major metabolite 5-hydroxyindoleacetic acid (5-HIAA), are indispensable for the elucidation of their (patho)physiological roles. In clinical chemistry attention is mainly focused on the diagnosis and follow-up of carcinoid tumours. For this most laboratories routinely measure urinary 5-HIAA. More recently, measurements of serotonin in platelets and urine have been advocated. Platelet serotonin may be the most sensitive indole marker for the detection of carcinoid tumours that secrete only small amounts of serotonin and/or its precursor 5-hydroxytryptophan. Although several chromatographic techniques have emerged for the analysis of tryptophan-related indoles, HPLC with either electrochemical or fluorometric detection have become the methods of choice for their quantification. HPLC-based methods combine selectivity, sensitivity and high precision, and enable the simultaneous investigation of several metabolically related indoles. This review aims to place the analysis of indoles in biological matrices in a biochemical, physiological and clinical perspective and highlights several important steps in their chromatographic analysis and quantification.
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Affiliation(s)
- I P Kema
- Department of Pathology and Laboratory Medicine, University Hospital Groningen, The Netherlands
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